As Florida’s legislative session ends, the fight for the Republican nomination to take on Sen. Bill Nelson (D) begins in earnest. For the three major GOP candidates in the race, it’s going to be a long, nasty campaign slog, full of sound and fury.

The always-battleground Florida swung substantially Republican in 2010 — leaving Nelson the lone Democrat to hold statewide office — but 18 months out, Nelson finds himself in a surprisingly strong position.

“Do not underestimate him,” former Sen. Mel Martinez (R) told Roll Call. “I think he’ll be a formidable candidate in his re-election effort.”

The Republicans aiming to win over GOP voters and attempting to topple the two-term Democrat are state Senate President Mike Haridopolos, former state House Majority Leader Adam Hasner and former Sen. George LeMieux. LeMieux may have the most difficult task: distancing himself from the man who appointed him to serve two years as Senator, former Gov. Charlie Crist.

Crist became political anthrax when he fled the GOP to run as an independent against a surging Marco Rubio, who was poised to defeat him.

“There is no one more toxic in Republican circles than Charlie Crist,” said Phil Vangelakos, a Republican consultant based in Orlando.

Hasner has already leveraged LeMieux’s 2009 appearance with Crist, when LeMieux described himself “as a Charlie Crist Republican.” Hasner turned the news clip into a campaign Web ad via charliecristrepublican.com. The tagline of the video: “We need conservative reinforcements in Washington, not reinventions.” In all likelihood, some version of this video will be seen on TV before the primary is over, but LeMieux says voters are “too smart” to be distracted by those types of attacks.

“Who I worked for in the past is not going to decide this election,” LeMieux told Roll Call in an interview. He said he is the only major GOP candidate who never voted for a tax increase and noted his fiscally conservative record during his time in the Senate.

“It would honestly be a lot smarter for me — a guy who’s got four kids who are 7 and under, who has a really great job helping to run a statewide law firm — to not run. A lot of my friends think I need to have my head examined,” LeMieux said, adding that the debt crisis is why he wants his job back.

Tampa-based Republican consultant Chris Ingram predicted LeMieux’s Crist remark will “haunt him until primary day” in August 2012. “It’s going to be probably the single most defining factor in his defeat,” Ingram said.

The eventual GOP nominee will face the significant challenge of battling Nelson in a presidential election year when President Barack Obama’s campaign is expected to pour as much as $100 million into the swing state of Florida.

Nelson has never been a vastly popular figure in the state, nor has he been particularly unpopular. A Quinnipiac University poll of registered Florida voters released last month found 47 percent approved of how he was handling his job, while 27 percent disapproved.

Polls show the three Republicans with low name recognition statewide. The National Republican Senatorial Committee views Florida as one of its top pickup opportunities, and Democrats recognize protecting Nelson must be among their top defensive priorities. That’s one reason Obama held his first fundraiser of the 2012 season in Miami with Nelson by his side. Roll Call Politics rates this race a Tossup.

Top strategists in Florida say that lack of enthusiasm among the Democratic base in Florida might have been Nelson’s downfall if he’d had to run in 2010. Former Rep. Kendrick Meek, the Democratic nominee for Senate in 2010, received only 20 percent of the vote. But 2012 could be a different story with a fired-up base.

Consultant Steve Schale, who ran Obama’s 2008 campaign in Florida, told Roll Call that Nelson has been traditionally weak in getting Democratic voters excited. But Schale believes having Obama at the top of the ticket can help Nelson counterbalance that problem in 2012.

All three GOP candidates face institutional problems. As current and former state legislators, Haridopolos and Hasner could have difficulty getting a foothold statewide.

“It used to be that the legislature was the cauldron of statewide political leadership,” former Florida Sen. Bob Graham (D) told Roll Call. “Most governors and many U.S. Senators had had legislative experience before they” were elected statewide. Today, term limits and other factors don’t really allow them “the chance to develop a statewide constituency,” Graham said.

Rubio, a former Florida Speaker, is the big exception. That’s thanks in part to Crist, who was damaged by Rubio’s decision to use footage of the governor hugging Obama as he endorsed the president’s stimulus package.

LeMieux’s rivals hope the video of him standing with Crist has the same effect.

Influential conservative blogger Erick Erickson of Red State called LeMieux “former Senator George LeCrist” in a post endorsing Hasner. Erickson was an early Rubio backer, and he got involved in 2010 primaries that in several instances delivered surprising wins for conservative candidates over the establishment’s favored pick. (For his part, Rubio is staying out of the primary.)

A lawyer and businessman, Hasner is working to position himself to the right of his opponents.

Local tea party activists said they are not excited about the field but they are keeping an open mind among the contenders. The conservative Club for Growth is meeting with some of the candidates and is considering getting involved in the primary.

Haridopolos’ biggest weakness could be his ethical troubles. He was cited by the state Senate for failing to disclose all of his sources of income on required filings. Then there’s the $152,665 he was paid by Brevard Community College to write his benign-sounding book “Florida Legislative History and Processes.” The school did not make the manuscript publicly available until more than four years after Haridopolos submitted the text, prompting ethics questions that state Democrats have been happy to exploit.

Weaknesses aside, Sunshine State consultants say no candidate has lit a fire with voters.

“In a presidential year, it’s going to take perfect execution and a Republican candidate who can inspire a movement,” Vangelakos said.

Ingram said the most consistent comment he gets from GOP voters “is that they hope someone else emerges into the field.”

Who that someone else is remains unclear, but it’s a narrative national Democrats love. “Even establishment Republicans and rank-and-file conservatives recognize that their candidates are deeply flawed,” Democratic Senatorial Campaign Committee spokesman Shripal Shah said.

Hasner and LeMieux have not filed reports with the Federal Election Commission, but Haridopolos’ campaign is already a fundraising juggernaut. The Florida Senate president raked in
$2.6 million in the first quarter of this year. Nelson raised $1.8 million last quarter and had a comfortable $4.6 million in the bank as of March 31.

But Republicans have not let the Democrat’s significant bankroll keep them from taking aim at someone they see as beatable.

Nelson’s office declined to answer campaign questions.

“The election’s 19 months away,” Nelson spokesman Dan McLaughlin told Roll Call. “Come election time, if the folks in Florida like the way Nelson’s been working for them, then the politics will take care of itself.”