TALLAHASSEE, Fla. — Floridians could help determine control of the U.S. Senate on Tuesday as they decide whether to keep three-term incumbent Democrat Bill Nelson in office or replace him with Republican Gov. Rick Scott.

Nelson has been viewed as one of the nation’s most vulnerable Democrats thanks to the formidable challenge from Scott, a multimillionaire businessman who has poured more than $60 million of his own fortune into the contest. A Nelson loss could make it difficult for Democrats to take back the Senate.

While the two men differ on a range of issues ranging from gun control to health care, the election has been more about character and competence and the candidates’ respective relationships with President Donald Trump.

Scott has urged voters to “retire” the 76-year-old Nelson, calling him ineffective and faulting him on everything from the level of federal support for the space program to the slow wait to get federal money to help repair the Lake Okeechobee dike.

“I work and he doesn’t,” said Scott. “He doesn’t do anything. I don’t know what he has done in 42 years of office.”

That message has resonated with voters such as Ed Evangelista, who attended a Trump political rally this week in southwest Florida. He recently moved to the state after living in Connecticut for most of his 70 years.

In his home state, he said he voted for Democrats and Republicans. Now that he lives in Venice, Florida, he’s casting his first ballot in the state for Scott.

“He’s been in way too long,” Evangelista said of Nelson. “I don’t care if he’s a good guy or not.”

Nelson has responded by branding Scott as a Trump follower who has used the governor’s office to pad his wealth and has ignored problems festering in the state. He has insisted Scott’s actions to cut the budgets of water-management districts and limit enforcement actions at the state’s environmental agency have contributed to the toxic algae and red tide that have plagued the coast this year. Nelson has also criticized Scott for opposing President Barack Obama’s federal health care overhaul.

“The campaign is about trust and integrity,” Nelson said during a campaign swing through Tallahassee with Vice President Joe Biden. “I think the choice is pretty clear. You just can’t trust Rick Scott. He’ll either change his position or he goes completely against the public interest.”

When Scott first decided to run, the contest between him and Nelson was seen as one of the marquee races in the nation, involving two heavyweights.

But that battle has been overshadowed by the governor’s race, a vitriolic contest between Republican Ron DeSantis and Democrat Andrew Gillum that’s been seen as a proxy battle between Trump and Democrats. Scott also spent nearly two weeks off the campaign trail to respond to Hurricane Michael, which pummeled several counties in the Florida Panhandle and was responsible for dozens of deaths.

Scott, a one-time health care executive, jumped into politics eight years ago and rode a tea party wave into the governor’s office. He promised to enact stiff new policies to deal with immigration and was a loud critic of Obama. While in office, Scott backed away from his hard line on immigration and even came out in support of Medicaid expansion, although he changed that position once he was re-elected.

The 65-year-old governor planned to make the election a referendum on Nelson’s tenure, but found himself playing defense over his own record and became the target of vocal protests at some of his campaign stops.

The governor also began widely airing a television ad promising to retain the Affordable Care Act’s consumer protections for people with pre-existing conditions, even though Florida is one of the states involved in a lawsuit aimed at overturning the federal law. The governor has maintained he had nothing to do with the lawsuit, but he has not called for the state to withdraw from it.

Nelson and his allies ran ads questioning Scott’s ethics, pointing to his ouster as chief executive of health care giant Columbia/HCA amid a federal fraud investigation. Although Scott was never charged with any wrongdoing, the health care conglomerate paid a then-record $1.7 billion fine for Medicare fraud.

Nelson, whose long political career included a stint as the state’s insurance commissioner, has been put on the defensive this election season, as well, particularly over several public comments and statements.

Over the summer he triggered a firestorm when he said the Russians were meddling in Florida’s election system after an unsuccessful attempt in 2016. While top GOP senators would neither confirm nor deny Nelson’s statement, federal authorities told Florida election officials they saw no signs of any “new or ongoing compromises” of state or local election systems.

More recently, Nelson warned that the ongoing political strife in the nation could lead to the genocide that happened in the African nation of Rwanda, where nearly a million people were killed in the early ’90s.