Washington (CNN) - Florida Gov. Charlie Crist's expected announcement Thursday that he is giving up his bid for the Republican party's Senate nomination and instead running as an independent is just one chapter in a wider war for the heart and soul of the GOP.
Next week, the spotlight will move to Indiana, where former Sen. Dan Coats is hoping to win back his old seat. The former Republican lawmaker, who is the establishment candidate in the race, is facing off against a number of opponents in Tuesday's primary, including former Rep. John Hostettler and state Sen. Marlin Stutzman.
Conservative Sen. Jim DeMint of South Carolina has endorsed Stutzman, who is also the favorite of local Tea Party groups in Indiana. On Wednesday, a political action committee that DeMint chairs announced it has raised over $200,000 in campaign donations for Stutzman, who was once a long shot in the primary contest.
The winner of the primary will take on Democratic Rep. Brad Ellsworth in the general election. The race is to fill the seat being vacated by Democratic Sen. Evan Bayh.
Bitter Republican primary fights are also being waged in half a dozen states nationwide.
In Utah, Republican Sen. Bob Bennett, who no one would call a moderate, is fighting for his political life because he may not be conservative enough. Bennett upset many on the right with his 2008 vote in favor of the federal bailout of banks and financial institutions. The fiscally conservative Club for Growth has been actively working to defeat Bennett, as have some Tea Party organizations.
Bennett, who is fighting for a third term in the Senate, may not even make it to his party's primary. He needs to win the votes of at least 40 percent of the 3,500 delegates attending the Utah GOP convention on May 8 to advance to a June primary. Two recent polls suggest that may be a tough task.
Kentucky holds its primary 10 days after the convention in Utah, and the Republican race there is shaping up as another battle between the party favorite and the conservative outsider.
Trey Grayson, the Kentucky secretary of state and establishment candidate in the race, was the early favorite. But Rand Paul, a physician and the son of former GOP presidential candidate and Texas Rep. Ron Paul, now leads in the battle for the nomination, according to some recent polls.
Paul has the backing of some Tea Party groups and has been endorsed by former Alaska Gov. Sarah Palin, a darling of conservatives. Both Paul and Grayson are fighting to succeed Sen. Jim Bunning, a fellow Republican who is not running for re-election this year.
The conservative vs. moderate and insider vs. outsider dynamics are also playing out in Republican Senate primary contests in California, Colorado, and Arizona.
But Sen. John Cornyn of Texas says party primaries "are good for culling the weak from the strong."
The chairman of the National Republican Senatorial Committee, which assists incumbent GOP senators running for re-election and Republican candidates seeking office, was an early backer of Crist in the Florida contest.
Cornyn told reporters on Wednesday that his early endorsement of Crist last year was a bad idea in hindsight. He says he has realized that "it's not necessarily helpful" for the NRSC to endorse statewide candidates in light of the current anti-establishment and anti-incumbent mood in the country.
The mood helps Republicans over Democrats in this November's contests, since the Democrats control Congress and the White House and since there are more Democratic than Republican incumbents up for re-election this year. But victories by conservative candidates over more moderate Republicans in the spring and summer primaries could hurt the GOP as it bids for moderate and independent voters in November's general elections.
Follow Paul Steinhauser on Twitter: @psteinhausercnn