One of the most intriguing story lines of the 2010 election cycle will reach a crescendo today in St. Petersburg, where Florida Gov. Charlie Crist is expected to formally launch an Independent Senate campaign.

Crist’s move to abandon his GOP bid comes after weeks of increasing speculation that he would do so, despite his repeated denials. And while those who know the governor say he could still change his mind at the last minute, the reports out of Florida on Wednesday that Crist was informing supporters he would run with no party affiliation came as no surprise to House Republicans in the Sunshine State delegation.

“It’s become increasingly clear that he’s been inclined to place his own political fortunes above a common set of guiding philosophies,” said Rep. Adam Putnam, who is running for Florida agriculture commissioner. “I expect the vast majority of Republicans will support the Republican candidate.”

Rep. Bill Young (R), whose district covers much of Crist’s St. Petersburg home turf, said Crist is entitled to make the decision to leave the Republican Party — even if it is the wrong one.

“I think that was a mistake, but that might be his only chance to win that Senate seat,” Young said. “I’ll support the Republican candidate.”

Rep. Tom Rooney (R) said Crist gave up on his party too soon.

“I was still holding out that [Crist] would come out [Thursday] and say, ‘I’m a Republican and if I lose as a Republican then so be it.’ I think he actually would have gotten a lot of support for that,” Rooney said. “There is a long time before the election. He has a lot of money to show people what kind of Republican he could have been.”

He added, “Unfortunately, that is not going to happen and Marco is going to be a great Senator.”

Rep. Jeff Miller (R), who endorsed former State Speaker Marco Rubio in the GOP Senate primary in June 2009, said Crist’s decision was selfish.

“I think it’s pretty self serving for the governor to leave the party that has supported him to run for the Senate only when it became apparent he was not going to be the Republican nominee,” Miller said.

Miller added that Crist should return money to contributors who no longer wish to support his Senate bid.

Another Rubio supporter on Capitol Hill, Sen. Jim DeMint (R-S.C.), had even stronger words Wednesday.

“That’s what you get when the numbers matter and the principles don’t. I’m just happy that Marco Rubio is going to be our nominee; he’s a good candidate. I’m very disappointed that Crist would abandon our party because the numbers didn’t look good for him,” he said.

Crist’s move to leave the party comes just two weeks shy of the one-year anniversary of the National Republican Senatorial Committee hailing him as “a dedicated public servant and a dynamic leader” in its endorsement of his Senate campaign.

Since then, Crist has suffered one of the deepest and quickest descents in recent political history. It was a fall that may have been triggered by changes in the national political landscape, but it was accelerated by Crist’s own history of antagonizing party stalwarts when the moment suited him.

Among the more pointed examples came in the final days of the 2006 election cycle, when President George W. Bush traveled to Pensacola as part of his final get-out-the-vote effort. He was scheduled to appear at a campaign event with Crist, but in a bold move, the GOP gubernatorial candidate decided at the last minute to blow off the president. As the story goes, Crist’s chief of staff, now-Sen. George LeMieux (R), had convinced Crist the conservative area of the Panhandle was safely in his camp and that he needed to campaign elsewhere in the state.

But the move clearly embarrassed the White House. When CNN asked top Bush adviser Karl Rove why Crist had ditched the rally that day, Rove angrily told the reporter to “ask George LeMieux.”

LeMieux, whom Crist appointed to the Senate to temporarily fill the seat being contested in November, declined to talk with reporters on Wednesday about Crist’s decision to leave the GOP.

And George W. wasn’t the only Bush whom Crist snubbed.

Upon taking office, one of Crist’s first official acts was to revoke nearly 300 appointments made by his predecessor, Republican Jeb Bush. In the policy realm, Crist put his own mark on several of what were seen as Bush’s legacy programs, such as the Florida Comprehensive Assessment Test for schools and Bush’s One Florida affirmative action initiative.

“Gov. Bush was someone who placed policy above all else,” said Albert Martinez, who worked as an aide to the former governor and now works as an adviser to Rubio. “He suffered a lot of slings and arrows for [One Florida], but he stuck with it. … When Gov. Crist came in, it was never about the policy. It was about the politics.”

But Martinez said Crist has also fumbled what the former governor handed him in the political realm.

“Jeb Bush basically helped build the Republican Party of Florida from nothing into one of the most envied state parties in the country” by the time he left office, Martinez said.

Pointing to the recent scandals involving fiscal mismanagement and credit card use that led to Crist’s appointed state party chairman stepping down earlier this year, Martinez said, “Crist took that and in four years has destroyed it.”

Still, the most famous case of Crist aggravating Republicans took place when he gleefully accepted federal money for Florida from the hotly disputed stimulus package.

Crist outraged many in his party by appearing at a Fort Myers rally with President Barack Obama while that legislation was still being fiercely debated on Capitol Hill. At that event, Crist gave the president a warm embrace that was captured on camera.

Rubio used the image to launch his campaign in 2009 and has rallied conservatives to his cause with it ever since.

“It was a slow build that led to the hug,” said David Johnson, a Florida Republican consultant and former state GOP executive director. But after it happened, “the hug was the straw that broke the camel’s back. … When George Bush came to Florida, [Crist] didn’t stand with him. But he sure was there when Obama showed up.”

David M. Drucker contributed to this report.