>>> TONIGHT, THE DRAMA IN THE COURTROOM. DONALD TRUMP CLASHING WITH THE JUDGE IN THE FRAUD TRIAL THREATENING HIS BUSINESS EMPIRE. THE FORMER PRESIDENT TAKING THE STAND, LASHING OUT AT THE JUDGE AND NEW YORK'S ATTORNEY GENERAL. THE JUDGE WARNING HIM, QUOTE, THIS IS NOT A POLITICAL RALLY. MR. TRUMP EMERGING, MAKING A ZIPPED LIPS GESTURE AT THE CAMERAS. DID HE HELP OR HURT HIS CASE? OUR TEAM STANDING BY. >>> ALSO TONIGHT, ISRAELI FORCES ENCIRCLING GAZA CITY, EXPECTED TO ENTER IT SOON. OUR RARE ACCESS INSIDE GAZA. OUR CORRESPONDENT EMBEDDED WITH ISRAELI TROOPS TASKED WITH HUNTING AND DESTROYING HAMAS'S MAZE OF TUNNELS. >>> THE FATHER CHARGED AFTER HIS SON WAS ACCUSED OF FATALLY SHOOTING SEVEN PEOPLE AT AN ILLINOIS FOURTH OF JULY PARADE. THE SURPRISE IN COURT JUST BEFORE HIS TRIAL WAS SET TO BEGIN. >>> ELECTION DAY 2024 NOW LESS THAN A YEAR OUT. AND THE MAJOR WARNING SIGNS FOR PRESIDENT BIDEN. WHAT NEW BATTLEGROUND POLLS ARE SHOWING TONIGHT. >>> AND AHEAD OF OUR GOP PRESIDENTIAL DEBATE HERE IN MIAMI OUR NBC NEWS BROADCAST EXCLUSIVE. KIM REYNOLDS, THE GOVERNOR OF ALL-IMPO LESS THAN A YEAR AGO. HIS EMOTIONAL MESSAGE. >> Announcer: THIS IS NBC "NIGHTLY NEWS" WITH LESTER HOLT. >>> GOOD EVENING, EVERYONE. REPUBLICAN FRONT-RUNNER DONALD TRUMP WAS CENTER STAGE TODAY IN MANHATTAN AS THE REST OF THE FIELD READIES TO DEBATE IN MIAMI. HE WAS THE CENTER OF AN EXTRAORDINARY LEGAL AND POLITICAL MOMENT, TAKING THE WITNESS STAND AT HIS CIVIL FRAUD TRIAL. HIS TESTIMONY FRAMED BY FLASHES OF ANGER, DEFIANCE AND DISDAIN FOR THE PROCESS. DEFENDING HIMSELF AGAINST ALLEGATIONS HE INFLATED THE VALUATION OF HIS ASSETS TO GET MORE FAVORABLE TREATMENT ON BANK LOANS. IT COMES ONE YEAR BEFORE THE 2024 PRESIDENTIAL ELECTION, WITH MR. TRUMP THE LEADER BY A WIDE MARGIN. TODAY IN COURT MR. TRUMP AGAIN ATTACKED THE TRIAL AS ELECTION INTERFERENCE AND CALLED IT RIDICULOUS. AT ONE POINT THE JUDGE TELLING MR. TRUMP'S LAWYER TO CONTROL HIM, SAYING "THIS ISN'T A POLITICAL RALLY." NONE OF IT SEEMS TO BE HAVING AN EFFECT ON MR. TRUMP'S POLITICAL FORTUNES SO FAR. NEW POLLING SHOWING HIM LEADING PRESIDENT BIDEN IN FIVE KEY BATTLEGROUND STATES. WE'LL GET TO THAT IN A MOMENT. BUT FIRST, SENIOR LEGAL CORRESPONDENT LAURA JARRETT ON THE FORMER PRESIDENT'S DAY IN COURT. >> Reporter: TONIGHT, A COMBATIVE DONALD TRUMP TESTIFYING FOR HOURS IN A MANHATTAN COURTROOM WITH HIS REAL ESTATE EMPIRE ON THE LINE. >> THIS TRIAL IS RIDICULOUS. >> Reporter: MR. TRUMP SHOWING FLASHES OF ANGER AS HE SPARRED WITH THE JUDGE AND THE NEW YORK ATTORNEY GENERAL'S OFFICE, BRUSHING OFF ACCUSATIONS THAT HE DOCTORED FINANCIAL STATEMENTS TO INFLATE THE VALUE OF SOME OF HIS MOST WELL-KNOWN PROPERTIES LIKE MAR-A-LAGO, TRUMP TOWER AND 40 WALL STREET, ALL TO DEFRAUD BANKS AND LENDERS. >> BUT AT THE END OF THE DAY THE ONLY THING THAT MATTERS ARE THE FACTS AND THE NUMBERS. AND NUMBERS, MY FRIENDS, DON'T LIE. >> Reporter: ALREADY FOUND LIABLE FOR FRAUD, THE FORMER PRESIDENT NOW TRYING TO FEND OFF A $250 MILLION PENALTY. GROWING HEATED TODAY WHEN PRESSED ABOUT WHETHER HE OVERVALUED ASSETS FOUND IN THE TRUMP ORGANIZATION'S ANNUAL FINANCIAL STATEMENTS. HIS FACE TURNING RED, RAISING HIS VOICE, POINTING DIRECTLY AT THE JUDGE SEATED INCHES AWAY, YELLING "HE CALLED ME A FRAUD AND HE DIDN'T KNOW ANYTHING ABOUT ME." A REFERENCE TO THE JUDGE'S PRETRIAL DECISION THAT RULED IN THE STATE'S FAVOR. ALSO GOING AFTER THE ATTORNEY GENERAL HERSELF, WATCHING ON IN THE COURTROOM. MR. TRUMP CALLING HER A POLITICAL HACK. >> I WILL NOT BE BULLIED. I WILL NOT BE HARASSED. THIS CASE WILL GO ON. >> Reporter: AND MR. TRUMP DID MAKE SOME CONCESSIONS, ADMITTING TODAY HE PROBABLY SAW SOME OF THE DISPUTED FINANCIAL STATEMENTS THAT WENT TO BANKS AND LENDERS WHILE REPEATEDLY DISMISSING THEM AS NOT IMPORTANT BECAUSE THEY INCLUDED CERTAIN DISCLAIMERS, SAYING TODAY THAT HIS NET WORTH IS ACTUALLY FAR GREATER THAN WHAT'S REFLECTED IN HIS FINANCIAL STATEMENTS, TOUTING THE VALUE OF THE TRUMP BRAND. >> THE NUMBERS ARE MUCH GREATER THAN ON THE FINANCIAL STATEMENT. AND WE'VE ALREADY PROVEN THAT. THEY SAID MAR-A-LAGO'S WORTH $18 MILLION. MAR-A-LAGO'S WORTH ANYWHERE FROM PROBABLY 50 TO 100 TIMES MORE THAN THAT. >> Reporter: THE JUDGE'S PATIENCE TESTED AT TIMES BY THAT SAME RHETORIC ON THE WITNESS STAND, CALLING PARTS OF MR. TRUMP'S TESTIMONY IRRELEVANT AND RAMBLING, WARNING THE REPUBLICAN FRONT-RUNNER, "THIS IS NOT A POLITICAL RALLY." >> AND LAURA, MR. TRUMP'S LAWYERS ALSO SIGNALING TODAY THEY PLAN TO ASK FOR A MISTRIAL. >> Reporter: THAT'S RIGHT, LESTER. MR. TRUMP'S DEFENSE ATTORNEYS BELIEVING THAT THE JUDGE AND HIS LAW CLERK ARE SOMEHOW BIASED AGAINST HIM, SAYING THAT THEY INTEND TO FILE THAT MISTRIAL MOTION SOON. BUT FOR NOW, LESTER, THIS CASE MOVES FORWARD WITH IVANKA TRUMP SET TO TESTIFY WEDNESDAY MORNING. LESTER? >> ALL RIGHT, LAURA, THANKS VERY MUCH. I WANT TO TURN TO THE MODERATOR OF "MEET THE PRESS" KRISTEN WELKER. KRISTEN, WHAT'S THE POLITICAL FALLOUT? DO WE EVEN KNOW AT THIS POINT? OF A FORMER PRESIDENT ON THE WITNESS STAND. >> IT'S A GREAT QUESTION, AND THAT'S WHAT'S SO STUNNING, LESTER. THIS IS THE FIRST TIME IN MORE THAN 100 YEARS THAT AN EX-PRESIDENT HAS TESTIFIED IN COURT IN HIS OWN DEFENSE. STILL, ONE TRUMP ALLY TELLS ME IT'S A CHANCE FOR HIM TO FUND-RAISE AND TO MAKE HIS CASE TO HIS SUPPORTERS THAT THE TRIAL IS A PART OF A BROADER POLITICAL PERSECUTION DESPITE THE FACT THAT THERE'S NO EVIDENCE OF THAT. MR. TRUMP HAS COMMANDING LEAD IN THE PRIMARY AND HIS LEGAL BATTLES HAVE ONLY EMBOLDENED HIM. LESTER, IT COULD BE A DIFFERENT STORY IN A GENERAL ELECTION WHERE INDEPENDENTS AND MODERATE REPUBLICANS COULD BE TURNED OFF BY ALL OF THESE LEGAL BATTLES. >> LET'S TALK FOR A MOMENT ABOUT THE SITTING PRESIDENT. PRESIDENT BIDEN RIGHT NOW, SOME BAD POLL NUMBERS. >> THAT'S FOR SURE. DEMOCRATS ARE LOOKING AT THIS. THE LATEST "NEW YORK TIMES"/SIENA COLLEGE POLL SHOWS THAT PRESIDENT BIDEN IS TRAILING TRUMP IN FIVE OUT OF SIX SWING STATES THAT MR. BIDEN WON IN 2020, WITH MR. TRUMP GETTING HIGHER MARKS ON THE ECONOMY IN ALL OF THEM. NOW SOME DEMOCRATS SAYING LOOK, THEY'RE NOT PANICKING, IT'S TOO EARLY, THE ELECTION IS STILL A YEAR OUT AND FORMER PRESIDENT OBAMA TRAILED IN 2011 BEFORE DEFEATING MITT ROMNEY. BUT I SPOKE TO MULTIPLE DEMOCRATS TODAY WHO SAY THEY ARE DEEPLY CONCERNED, ONE CALLING IT A FIVE-ALARM FIRE, AND FORMER TOP OBAMA ADVISER DAVID AXELROD PUT IT THIS WAY. "IF HE CONTINUES TO RUN, HE WILL BE THE NOMINEE OF THE DEMOCRATIC PARTY. WHAT HE NEEDS TO DECIDE IS WHETHER THAT IS WISE, WHETHER IT'S IN HIS BEST INTEREST OR THE COUNTRY'S." SO HIGH STAKES HERE, LESTER. >> ONE YEAR TO GO. KRISTEN, THANKS VERY MUCH. >>> LET'S GET NOW TO THE DEEPENING ISRAELI MILITARY CAMPAIGN IN GAZA. THE DEATH TOLL IS RISING NOW ONE MONTH AFTER HAMAS TERRORISTS KILLED 1,400 ISRAELIS. CHIEF FOREIGN CORRESPONDENT RICHARD ENGEL HAS LATE DETAILS. >> Reporter: ISRAELI TANKS AND TROOPS HAVE ENCIRCLED GAZA CITY AND ARE EXPECTED TO SOON ENTER THE URBAN AREAS. THE HAMAS-RUN HEALTH MINISTRY IN GAZA SAYS THE DEATH TOLL HAS PASSED 10,000 AND THAT COULD RISE WITH AN ADVANCE INTO GAZA CITY, WHICH IS FULL OF HAMAS TUNNELS, FIGHTERS AND SEVERAL HUNDRED THOUSAND PALESTINIAN CIVILIANS. SECRETARY BLINKEN IS PUSHING ISRAEL TO PAUSE. BUT THERE'S NO SIGN THAT'S COMING. AS ANGER IN THE MIDDLE EAST AGAINST THE U.S., ISRAEL'S MAIN BACKER, IS GROWING. BEFORE BLINKEN ARRIVED IN TURKEY, PROTESTERS TRIED TO STORM A NATO BASE HOUSING AMERICAN TROOPS. A SECOND AMERICAN AIRCRAFT CARRIER STRIKE GROUP ARRIVED IN THE REGION IN A WARNING TO IRAN AND ITS PROXIES. AS U.S. OFFICIALS TELL NBC NEWS, THAT RECENT ATTACKS BY IRANIAN-BACKED MILITIAS HAVE INJURED AT LEAST 45 AMERICANS ON BASES IN IRAQ AND SYRIA. THEIR PACE INCREASING WITH TEN ATTACKS SINCE THURSDAY. NONE OF THE INJURIES WERE DESCRIBED AS LIFE-THREATENING. IN GAZA ISRAEL SAYS IT HAS LEFT OPEN A CORRIDOR FOR CIVILIANS TO ESCAPE FROM THE NORTH TO THE SOUTH. BUT IT'S NOT SAFE IN THE SOUTH EITHER. OUR CREW FOLLOWED AN AMBULANCE TO A GROUP OF BUILDINGS JUST HIT, WITNESSES SAY, BY AN ISRAELI STRIKE IN KHAN YOUNIS. A BOY IS UNDER THE RUBBLE. HE'S TRAPPED, HEAD DOWN AND STRUGGLING TO BREATHE. OVER SEVERAL HOURS RESCUE WORKERS MANAGE TO GET HIM OXYGEN, REMOVE DEBRIS AND TURN HIM OVER. FINALLY, THEY PULL HIM OUT. HE'S ROLLED ONTO A STRETCHER AND TAKEN TO AN AMBULANCE WHERE WE LEARN HIS NAME. 13-YEAR-OLD MOHAMMED SHAKURA. DOCTORS SAY HIS LEGS AND HIPS ARE BROKEN. WITNESSES SAY AT LEAST SIX OTHERS WERE KILLED IN THE SAME STRIKE. YAEL SHOHAM IS ALSO TRAPPED IN GAZA. SHE'S 3 YEARS OLD AND WAS KIDNAPPED WITH HER FAMILY BY HAMAS ON OCTOBER 7th FROM KIBBUTZ BE'ERI. I MET HER UNCLE, YUVAL. ARE ALL THESE PEOPLE FROM YOUR FAMILY? >> THIS IS MY FAMILY. THIS IS MY MOTHER, SHOSHANA. AND THIS IS MY SISTER ADI AND HER HUSBAND, TAL. AND BOTH THEIR CHILDREN, NAVEh WHO IS 8 YEARS OLD AND YAEL, WE CALL HER YULA IS ONLY 3 YEARS OLD. WE'RE TALKING ABOUT A LITTLE GIRL WHO WAS NEVER AWAY FROM HER MOTHER. THEY ARE ALWAYS TOGETHER. THEY SLEEP TOGETHER. I DON'T EVEN KNOW IF ADI IS HUGGING HER NOW. WE DON'T KNOW IF THEY HAVE FOOD. WE DON'T KNOW IF THEY HAVE WATER. WE DON'T KNOW WHERE THEY ARE. WE DON'T KNOW IF THEY'RE TOGETHER. I CAN'T THINK ABOUT WHAT'S HAPPENING IN GAZA BECAUSE IT BREAKS MY HEART. ALL I CAN THINK ABOUT IS I WANT MY FAMILY BACK. I WANT TO KNOW THEY'RE ALIVE. >> RICHARD, WITH SO MANY DEAD IN THIS WAR ALREADY IT LOOKS LIKE IT COULD GROW DRAMATICALLY WORSE. >> Reporter: AS ISRAELI TROOPS START PUSHING DEEPER INTO GAZA CITY, THEY'LL BE FIGHTING ON FOOT, CLEARING BUILDINGS. THEY'LL BE USING A LOT OF COVER FIRE. IT WILL BE DANGEROUS FOR THEM, LETHAL FOR EVERYONE AROUND. SO CASUALTIES ALMOST CERTAINLY WILL GO UP. >> RICHARD ENGEL, THANK YOU. >>> A KEY TARGET OF THE ISRAELI MILITARY IS HAMAS'S VAST NETWORK OF TUNNELS IN GAZA. RAF SANCHEZ WAS ABLE TO ACCOMPANY AN IDF UNIT INSIDE GAZA. >> Reporter: SEVERAL MILES INSIDE GAZA, ISRAELI FORCES ARE ON HIGH ALERT. AT FIRST IT'S NOT CLEAR WHY. NOTHING IN THIS DEVASTATED LANDSCAPE LOOKS LIKE IT COULD CHALLENGE THEIR OVERWHELMING FIREPOWER. BUT FOR ISRAELI TROOPS THE THREAT IS COMING FROM BELOW. SQUADS OF HAMAS FIGHTERS BURSTING OUT OF TUNNELS TO MOUNT AMBUSHES LIKE THIS. >> THEY'RE COMING OUT. THEY'RE SHOOTING YOU. GOING BACK TO THE TUNNEL. AND THEN RUNNING TO ANOTHER TUNNELS. >> Reporter: NBC NEWS WAS GRANTED RARE ACCESS INSIDE GAZA BY THE ISRAELI ARMY FOLLOWING COMBAT ENGINEERS TASKED WITH BLOCKING THE TUNNELS AND STOPPING THE ATTACKS. AS A CONDITION OF JOINING THEM WE AGREED TO BLUR SOME FACES AND TO SHOW ISRAEL'S MILITARY CENSORS OUR RAW FOOTAGE THOUGH NOT OUR FINAL STORY. NEARLY ONE MONTH AFTER HAMAS TERRORISTS STORMED OUT OF GAZA THROUGH THIS BORDER FENCE WE JOINED A COLUMN OF ISRAELI TROOPS HEADING THE OTHER WAY. OUR FIRST STOP IS ONE OF THE ONLY HOUSES IN THE AREA STILL STANDING. THE FAMILY KITCHEN IS ABANDONED, BUT THE BACK YARD HOLDS A SECRET. >> THIS IS THE ENTRANCE TO ONE OF DOZENS OF TUNNELS THEY FOUND IN THIS AREA. THEY SAY IT'S ABOUT 15 YARDS DEEP, THAT HAMAS FIGHTERS POPPED OUT TO AMBUSH THEM FROM IT, AND THAT THEIR MISSION IS TO DESTROY THIS TUNNEL AND ALL THE OTHERS ACROSS GAZA. >> Reporter: IT'S NO EASY TASK. ISRAEL SAYS THERE'S A VAST NETWORK OF TUNNELS, CONCEALED BENEATH CIVILIAN AREAS. >> THEY NOW HIDE UNDER SCHOOLS AND UNDER HOSPITALS BECAUSE THEY KNOW THAT WE AS THE ISRAELI DEFENSE FORCES, WE WILL NOT ATTACK HOSPITAL OR WE WILL NOT. BUT THIS WAR WILL BE DIFFERENT. >> Reporter: ISRAEL CLAIMS IT HAS NO CHOICE BUT TO STRIKE IN DENSELY POPULATED AREAS. BUT THE TOLL ON PALESTINIAN CIVILIANS HAS BEEN DEVASTATING. NOT FAR AWAY MAJOR MAIYAN MULLA LEADS US THROUGH THE RUINS OF A BEACH RESORT. >> WE FOUND OUT THREE TUNNELS THAT CONNECTED TO EACH OTHER. >> Reporter: THEIR SOLUTION IS SIMPLE. GRAFFITI HERE READS "RETURN THE HOSTAGES." EVERY TUNNEL A POSSIBLE SITE OF CAPTIVITY. >> HAVE YOU SEEN ANY SIGN OF THE HOSTAGES? >> NO. UNFORTUNATELY, NOT YET. >> Reporter: A SEARCH THAT CONTINUES EVER DEEPER INTO THE STRIP. RAF SANCHEZ, NBC NEWS, NORTHERN GAZA. >>> JUST IN TONIGHT, THE VERDICT FOR A COLORADO POLICE OFFICER IN THE SECOND TRIAL OVER THE 2019 DEATH OF ELIJAH McCLAIN AFTER ONE DAY OF DELIBERATION. LET'S GET RIGHT TO STEVE PATTERSON. STEVE, WHAT HAPPENED IN THE COURTROOM? >> AND LESTER, A COLORADO JURY HAS FOUND AURORA POLICE OFFICER NATHAN WOODYARD NOT GUILTY OF RECKLESS MANSLAUGHTER AND CRIMINALLY NEGLIGENT HOMICIDE IN THE DEATH OF ELIJAH McCLAIN. PROSECUTORS ARGUED THAT WOODYARD PUT THE 23-YEAR-OLD UNARMED MAN IN A NECK HOLD AND THEN FAILED TO PROVIDE PROPER FOLLOW-UP CARE WHILE HE WAS DETAINED AND UNABLE TO BREATHE. BUT JURORS SIDED WITH THE DEFENSE'S ARGUMENT, THAT HE DID WHAT HE WAS TRAINED TO DO AFTER THE HOLD AND RELIED ON PARAMEDICS WHO ADMINISTERED KETAMINE. McCLAIN DIED IN 2019 AFTER BEING STOPPED BY POLICE WHILE WALKING FROM A CONVENIENCE STORE HOME, SPARKING NATIONWIDE PROTESTS. TWO OTHER OFFICERS WERE ALSO CHARGED, ONE ACQUITTED, THE OTHER FOUND GUILTY OF CRIMINALLY NEGLIGENT HOMICIDE. TWO PARAMEDICS WERE ALSO CHARGED IN McCLAIN'S DEATH. THEIR TRIAL IS SLATED FOR NOVEMBER. LESTER? >> ALL RIGHT. STEVE PATTERSON, THANK YOU. >>> A SURPRISE GUILTY PLEA TIED TO THE MASS SHOOTING AT A FOURTH OF JULY PARADE IN HIGHLAND PARK, ILLINOIS. ROBERT CRIMO JR. THE FATHER OF THE ALLEGED GUNMAN PLEADED GUILTY TO MISDEMEANOR RECKLESS CONDUCT. HE ADMITTED HE SIGNED HIS SON'S APPLICATION FOR A FIREARM OWNER'S I.D. CARD, KNOWING HE HAD EXPRESSED SUICIDAL AND VIOLENT THOUGHTS. INVESTIGATORS SAY THE SON USED THAT CARD TO BUY GUNS USED TO MURDER SEVEN PEOPLE. >>> IN 60 SECONDS, ALMOST FOUR MONTHS AFTER HOLLYWOOD ACTORS WENT ON STRIKE, THE STUDIOS HAVE GIVEN THEM A FINAL OFFER. WHAT THE ACTORS' UNION IS SAYING IN RESPONSE >>> JUST IN TONIGHT, SAG-AFTRA RESPONDING TO WHAT IT CALLS THE STUDIOS' FINAL OFFER TO END THE ACTORS' STRIKE. AMID SOME TROUBLING SIGNS AT THE FALL BOX OFFICE. WE GET MORE NOW FROM MIGUEL ALMAGUER. >> Reporter: IT'S THE HOLLYWOOD CLIFFHANGER NEITHER SIDE WANTED. TONIGHT AS THE ACTORS' STRIKE PLAYS OUT ON ITS 116th DAY, THEIR UNION, SAG-AFTRA, IS COUNTERING SEVERAL POINTS TO WHAT IT SAYS THE STUDIOS CALL THEIR LAST, BEST AND FINAL OFFER. THE DIRE WARNING PERHAPS THE LAST CHANCE TO SALVAGE THE START OF THE NEW 2024 TELEVISION SEASON AND THE CRITICAL ROLLOUT OF BLOCKBUSTER FILMS. >> THIS HAS BEEN A BATTLE FOR THE POWER AND DIRECTION OF HOLLYWOOD FOR NOT JUST THE NEXT THREE-YEAR CONTRACT THAT SAG-AFTRA ARE GOING TO SIGN BUT PERHAPS A GENERATION. >> Reporter: STILL AT ODDS OVER ISSUES LIKE STREAMING RESIDUALS, INSIDERS SAY ACTORS ARE UNWILLING TO WAVER OVER BETTER JOB ROLLOUT OF BLOCKBUSTERS LIKE "DUNE 2," PREVIOUSLY SCHEDULED FOR THIS WEEKEND, NOW DELAYED, THE BOX OFFICE JUST HAD ONE OF ITS WORST SHOWINGS THIS YEAR, GROSSING JUST $63 MILLION. >> THEY'VE HAD SEVERAL YEARS OF MAKING A LOT OF PROFIT, AND IT'S TIME TO CALL IT EVEN. >> Reporter: COSTING CALIFORNIA'S ECONOMY AN ESTIMATED $7 BILLION, TENS OF THOUSANDS OF JOBS HAVE BEEN LOST SINCE MAY. AND NOW ANOTHER PLOT TWIST. WILL THE LAST, BEST AND FINAL OFFER BE ENOUGH FOR A HOLLYWOOD ENDING? MIGUEL ALMAGUER, NBC NEWS, LOS ANGELES. >>> AND COMING UP, OUR EXCLUSIVE INTERVIEW WITH THE GOVERNOR OF IOWA. WILL HER -- WILL RON DeSANTIS BEING ENDORSED BY HER SHAKE UP THE PRIMARIES? >>> BACK NOW WITH OUR NBC NEWS EXCLUSIVE. AS THE GOP PRESIDENTIAL CANDIDATES PREPARE TO MEET ON OUR STAGE HERE IN MIAMI ON WEDNESDAY, ONE OF THEM, RON DeSANTIS, IS GETTING A MAJOR BOOST AS IOWA'S GOVERNOR MAKES A RARE ENDORSEMENT. BOTH SPOKE WITH DASHA BURNS. >> Reporter: TONIGHT GOVERNOR KIM REYNOLDS EXPLAINING WHY SHE'S BREAKING WITH THE IOWA TRADITION OF STAYING NEUTRAL AND ENDORSING RON DeSANTIS. >> I JUST FELT LIKE I COULDN'T SIT ON THE SIDELINES ANY LONGER. WE HAVE TOO MUCH AT STAKE. I TRULY BELIEVE THAT HE IS THE RIGHT PERSON TO GET THIS COUNTRY BACK ON TRACK. >> Reporter: IT'S ARGUABLY THE BIGGEST ENDORSEMENT OF THE PRIMARY AND A MUCH-NEEDED WIN FOR THE DeSANTIS CAMPAIGN, WHICH HAS INVESTED SIGNIFICANT TIME AND RESOURCES HERE. >> THIS ONE'S OBVIOUSLY VERY MEANINGFUL BECAUSE KIM HAS PROVEN TO BE A GREAT LEADER THAT IOWANS LOVE. >> Reporter: WITH TWO MONTHS TO GO, FORMER PRESIDENT TRUMP MAINTAINS A DOMINANT 27-POINT LEAD AMONG LIKELY IOWA CAUCUSGOERS WITH DeSANTIS AND NIKKI HALEY TIED FOR SECOND. >> FOR THOSE WHO CRITICIZE YOU AND SAY WHY ARE YOU ENDORSING A GUY WHO'S BEEN SLIPPING IN THE POLLS, TRUMP IS 30 POINTS AHEAD, WHAT DO YOU SAY TO THOSE CRITICS? >> I DON'T BASE MY DECISION ON POLLS. I TAKE A LOOK AT WHO I BELIEVE IS THE RIGHT PERSON FOR THE RIGHT JOB. I BELIEVE THAT RON IS THE RIGHT PERSON FOR THE RIGHT JOB. AND I BELIEVE HE'S GOING TO WIN. >> DO YOU WORRY ABOUT THE RISK THAT SHE'S TAKING BY ENDORSING YOU? >> NO, I DON'T. I MEAN, FIRST OF ALL, I RESPECT THE FACT THAT THAT'S NOT HER CALCULATION, WHICH IS RARE AMONGST ELECTED OFFICIALS. I'VE HAD PEOPLE COME TO ME AND SAY YOU KNOW, THAT THEY ENDORSED HIM BECAUSE OF THE THREATS AND EVERYTHING LIKE THAT. IF YOU CAN LOOK IN THE MIRROR AND SAY YOU DID WHAT YOU THINK IS RIGHT FOR THE RIGHT REASONS, THEN JUST LET THE CHIPS FALL WHERE THEY MAY. >> Reporter: MR. TRUMP WAS QUICK TO ATTACK GOVERNOR REYNOLDS FOR HER ENDORSEMENT, CALLING HER AMERICA'S MOST UNPOPULAR GOVERNOR. >> WHAT IS YOUR RELATIONSHIP LIKE NOW WITH THE FORMER PRESIDENT? >> WELL, I ASSUME IT'S -- WELL, I DON'T KNOW. I REALLY CAN'T TELL YOU. THAT'S PROBABLY A QUESTION FOR HIM. >> HAVE YOU SPOKEN WITH HIM RECENTLY? >> NO, I HAVEN'T. >> WHEN'S THE LAST TIME? >> PROBABLY THE LAST TIME HE CALLED TO ASK IF I WOULD ENDORSE HIM AND I SAID I WASN'T AT THIS POINT. >> Reporter: THE QUESTION NOW OF HER ENDORSEMENT OF DeSANTIS WILL MAKE A DIFFERENCE. >> I HOPE IT PERSUADES SOME OF THOSE VOTERS TO TAKE A LOOK AT HIM CLOSER. >> DOES IT IMPACT MY VOTE? I DON'T KNOW FOR SURE AT THIS POINT. HE'S BEEN ON MY RADAR. SO I -- MAYBE I'LL FEEL LIKE I'LL KNOW A LITTLE BIT MORE AFTER THE DEBATE. >> DO YOU BELIEVE TRUMP CAN'T WIN? >> YEAH, I BELIEVE HE CAN'T WIN. AND I BELIEVE RON CAN. >> Reporter: IF DeSANTIS WANTS TO PROVE TRUMP IS BEATABLE, HE'LL HAVE TO DO IT HERE. DASHA BURNS, NBC NEWS, DES MOINES, IOWA. >> AND JOIN US FOR THE REPUBLICAN PRESIDENTIAL DEBATE WEDNESDAY HERE IN JESSE KIRSCH, NBC NEWS, CINCINNATI. >>> AND THAT'S "NIGHTLY NEWS" FOR THIS MONDAY. THANK YOU FOR