Rep. Ron DeSantis is hoping to ride the wave of President Trump’s endorsement to victory in Florida’s GOP gubernatorial primary on Tuesday, as he battles state Agriculture Commissioner Adam Putnam in the costly and closely-watched contest.

The polls close in Florida -- where voters are choosing nominees for governor, senator and a slew of other offices -- at 7 p.m.

On Monday, Trump tried to help DeSantis over the finish line with a tweet of support. The current governor, Republican Rick Scott, is challenging incumbent Democratic Sen. Bill Nelson for the Senate.

“Congressman Ron DeSantis is a special person who has done an incredible job,” the president tweeted. “He is running in Tuesdays Primary for Governor of Florida….Strong on Crime, Borders and wants Low Taxes. He will be a great Governor and has my full and total Endorsement!”

Trump’s support has played a starring role in the race, with DeSantis securing the lead in polls after winning Trump's endorsement.

During a Fox News-sponsored debate in June, DeSantis played up Trump’s backing of his campaign, expressing doubt that Putnam adequately supports Trump. “I am proud to have the endorsement of President Trump in this race,” DeSantis said.

DeSantis, 39, is an Iraq War veteran and decorated military lawyer who has served in the U.S. House since 2013. He is a graduate of Yale University and Harvard Law School.

Putnam, 44, has also played up his support for Trump, but has emphasized, “I am focused on Florida.”

Putnam was elected as the state’s agriculture commissioner in 2010. He grew up on a cattle ranch and citrus grove, according to his campaign website, and has gotten the support of many Florida sheriffs.

Meanwhile, there’s a crowded Democratic primary for governor, including Tallahassee Mayor Andrew Gillum, Palm Beach billionaire Jeff Greene, former U.S. Rep. Gwen Graham, Orlando businessman Chris King and former Miami Beach Mayor Philip Levine.

Graham, a former congresswoman, has been consistently polling ahead seven points or more over her opponents.

Levine has spent millions of his own money and showed up Monday at the scene of the Jacksonville mass shooting to tout gun control.

Gillum, Tallahassee’s progressive mayor, hopes to be the first black governor of Florida and has the endorsement of the liberal Vermont Sen. Bernie Sanders.

As for the Senate race, Scott -- who was urged to run for the seat by Trump -- is expected to win the GOP primary. He would then face Nelson, considered one of the most vulnerable Democratic incumbents running for re-election to the Senate.

Republicans, trying to hold onto control of the Senate, are hoping Scott could flip the seat.

Trump narrowly defeated Democrat Hillary Clinton in Florida in the 2016 presidential race by less than 2 percentage points.



Trump, again, emphasized his support for Scott ahead of the election.

“Rick Scott of Florida is doing a fantastic job as Governor,” Trump tweeted. “Jobs are pouring into the State and its economic health is better than ever before. He is strong on Crime, Borders, and loves our Military and Vets. Vote for Rick on Tuesday!”

Elections are also taking place in Arizona, where three Republicans are facing off to replace outgoing Sen. Jeff Flake.

Officials in Arizona said Tuesday that problems with voting machines in several polling places temporarily prevented people from being able to cast ballots in the state's primary elections.

But a spokesman for Maricopa County, where the voting problems were reported, told Fox News on Tuesday afternoon that "all polling locations dealing with technical issues this morning have been fixed."

In the Senate race, two-term Rep. Martha McSally has emerged as the frontrunner in the GOP primary against former state Sen. Kelli Ward and Sheriff Joe Arpaio. The winner of this contest will likely face Democrat Kyrsten Sinema in November.

In the state’s governor’s race, President Trump has endorsed the re-election effort of Gov. Doug Ducey of Arizona, who is facing a challenge Tuesday from former Secretary of State Ken Bennett.

Oklahoma on Tuesday is also holding primary runoff elections, with focus on the Republican race between former Oklahoma City mayor Mick Cornett and Tulsa businessman Kevin Stitt.

Fox News’ Phil Keating, Peter Doocy, Kaitlyn Schallhorn and The Associated Press contributed to this report.