Voters hoping to find clarity by watching the first debate between Florida Gov. Rick Scott and U.S. Sen. Bill Nelson will need a political road map to navigate the litany of allegations the men threw at each other Tuesday. But this much will be abundantly clear when the taped event airs:

The most expensive U.S. Senate race in the country may also be the nastiest.

In a debate that will be translated into Spanish across five media markets — reaching a significant segment of the state's 2.3 million Hispanic voters — Nelson and Scott spit accusations at each other for an hour at the Miramar studios of Telemundo 51. Nelson called Scott a "walking conflict of interest" and serial liar, and the governor characterized the senator as a feckless career bureaucrat who bowed to communists in Cuba.

The two men turned questions about Obamacare, red tide and Russian hacking into answers about integrity, partisanship and mental capacity.

"Senator Nelson is confused," Scott said.

"You know, governor, you just can't tell the truth," Nelson said.

Fielding questions on an array of issues posed by moderators Jackie Nespral and Marilys Llanos, the Republican Scott and Democratic Nelson sought with each answer to further their narratives about their opponent. Nelson decried financial conflicts and false attack ads, while Scott constantly referred to Nelson's 40-year political career as an accomplishment-free wasteland.

Each landed blows in the first of two debates that could sway a tight and testy affair that may decide whether Republicans hold their 51-49 edge in the U.S. Senate. A RealClearPolitics average of polling in the race shows Nelson ahead by a single point as the first absentee ballots begin to go out in the mail.

Tuesday's debate will be aired in South Florida on Telemundo 51 and streamed in English on NBC Miami at 7 p.m. It will also air in Orlando, Fort Myers and in Tampa on Telemundo affiliates and on Comcast Channel 22 in West Palm Beach.

Placed opposite his challenger for the first time, Nelson blasted Scott for declining to expand Medicaid, which would have covered as many as 700,00 people in Florida. He ripped Scott for passing over $2.4 billion in federal spending for a high-speed rail project only to later invest in the parent company of the private Brightline passenger trains now running down the east coast. And he cited PolitiFact in describing Scott's campaign as a lie-filled smear intended to distract from eight failed years as governor.

"Whatever he says is simply not true," Nelson said. "He has nine attack TV ads on the air. A fact-checking independent organization has checked them and they're all false or either pants-on-fire false."

Scott — who argued that PolitiFact is "part of the Democratic Party" because it is "an arm of the Tampa Bay Times" — had his own shots for Nelson. (PolitiFact, which started as a project of the Tampa Bay Times in 2007, is now part of the Poynter Institute for Media Studies and is produced by independent journalists.)

Scott said that as governor, he worked to allocate state money toward repairs to the Herbert Hoover dike around Lake Okeechobee that could help reduce discharges of polluted water that have contributed to toxic blue-green algae blooms and perhaps an outbreak of red tide on both coasts. He accused Nelson of lying when he said over the summer that Russians had hacked the state's voting system (Nelson didn't respond). And he constantly repelled Nelson's attacks against Republicans by saying the 18-year senator has failed to find solutions for Florida despite having spent four decades in state and federal offices.

"This is why we need term limits," Scott said.

The opponents saved their daggers for the most visceral of topics.

Nelson, when a question was asked about gun control, introduced Fred Guttenberg, the father of a slain Marjory Stoneman Douglas High School student Jamie Guttenberg, and asked Scott to promise that he would stop supporting the legislation that earned him an A-plus rating from the National Rifle Association. (He didn't.)

Scott later introduced Sirley Ávila León, a Cuban woman who said Cuban state thugs were behind a machete attack that maimed her after she complained about a school closing. Scott asked Nelson to apologize for supporting Barack Obama's rapprochement with Cuba. (He didn't.)

"It's remarkable that Senator Nelson won't apologize," Scott said after Nelson responded by saying Cuban officials won't let him into the country because he's been so critical of the Castro regime.

That exchange could prove particularly important in a Spanish-language debate aired across half the state. Polls show the race is tight, and the same remains true for the margin between Scott and Nelson among Hispanic voters.

Among the politicians calling for the Justice Department to indict Raul Castro in the shoot-down of U.S. civilian rescue planes, Scott hammered Nelson for backing Obama's decision to ease restrictions on the Cuban government. Scott, who has also courted Venezuelan voters as their country goes through an economic crisis under socialist leader Nicolas Maduro, cast Nelson as soft on leftist dictators.

"He must have forgotten that when he teamed up with Barack Obama to do an appeasement with the Castro brothers," Scott said in retort to Nelson's call for a boycott on Venezuelan oil. "They've killed Americans. Imprisoned people for decades … Nothing changed. It was a unilateral concession."

But Nelson got his jabs in, too. He blasted Scott for a statement he made earlier in the campaign about how he wouldn't have done anything differently than President Donald Trump when it came to the federal response to Hurricane Maria in Puerto Rico.

"My opponent has said, when asked down there in Puerto Rico 'What would you have done differently?' He said 'I would not have done anything differently,'" Nelson said. "I think that pretty well tells you about the treatment of the people of Puerto Rico."

Polls show that Scott has polled well with Puerto Rican voters, even if Trump, for whom he chaired a political committee in 2016, is widely unpopular. Nelson, though, never mentioned Trump's name.

Scott and Nelson will meet again Oct. 16 on CNN.