After Rudy Giuliani’s expected third-place showing and possible exit from the race, the story coming out of tomorrow’s Florida primary may be Gov. Charlie Crist and whether or not he proves to be the kingmaker of the 2008 GOP election contest.

John McCain is sure hoping Crist’s got the power — having negotiated his endorsement over Rudy Giuliani, who was expecting it. Crist is a popular governor, so it’s possible the endorsement will make a few points’ difference, as one Florida Republican politico predicted it would in a conversation with National Review Online over the weekend. But others have their doubts.

Speaking in his capacity as a Florida voter and political observer, Robert F. Sanchez, policy director of the James Madison Institute (a Florida conservative think tank), says, “I think it may have arrived too late to make much of a difference.” He points to this year’s record-high early-voting turnout in Florida — which as of Friday night had already exceeded total turnout in Iowa, New Hampshire, and Nevada. “Record numbers of voters already had voted by the time Crist checked the public opinion polls and finally took a position,” Sanchez says.

Although the governor is popular, Sanchez notes “there is growing disenchantment with Crist among conservative Republicans…. Crist’s dalliance with radical climate change advocates does not sit well with global-warming skeptics. In particular, the state’s investor-owned utilities are chafing under his populist policies.”

Jeb Bush, the previous governor, is staying neutral in the primary, and his fans may recoil at following Crist’s lead. Sanchez says, “Crist’s decision to halt the statewide rollout of the market-based Medicaid reforms that Governor Jeb Bush and the legislature initiated in a five-county pilot project also galls many of the former governor’s loyalists.” He continues: “Blocking the expansion of those reforms, which saved the taxpayers money while also improving patient care, seems most untimely and counterproductive in a year when Florida, like most other states, is facing a downturn in state-government revenue because of the slowdown in housing.”

Sanchez adds: “Even among members of the general public, there is a growing realization that Crist has ‘over-promised and under-delivered’ on some important pocketbook issues — notably property insurance and tax cuts.”

Even if McCain does win tomorrow, the effect on Crist within Florida may be insignificant. Sanchez predicts the outcome of the presidential primary may be overshadowed by a referendum on tomorrow’s ballot on a proposed tax-cut amendment that Crist enthusiastically supports. “Public-opinion surveys suggest that it will lose, giving Crist an embarrassing defeat.”

Ultimately, Sanchez wonders if Rudy Giuliani’s weakness may be more valuable to McCain than Charlie Crist’s support. “When it became apparent that Giuliani was out of the running, many of his former supporters — deciding not to waste their vote — were up for grabs. Those for whom national security was the most important issue (and who, like Giuliani, were not overly concerned about illegal immigration) gravitated toward McCain, which probably helps to explain his rise in the polls.”

But it remains to be seen if either the Crist endorsement or the Rudy decline can put McCain over the top in Florida. Mitt Romney’s leading or tied in a number of polls, both in Florida and nationally. And while Fred Thompson has not endorsed anyone in the race, a number of former Fredheads and advisers — including Liz Cheney and former Republican congressman and Federalist Society co-founder David McIntosh — have joined the Romney campaign in recent days.

Another wild card is the Huckabee factor. Sanchez notes, “Thompson’s South Carolina debate barbs directed at Mike Huckabee may have hastened a Huckabee decline that the candidate lacked the funds to halt in this large state where media buys can be crucial.” Where his supporters will go is uncertain, but the former Arkansas governor clearly wants them to go to McCain — on Sunday he was echoing McCain’s attack on Romney for being weak on the Iraq surge (something Huckabee wasn’t known to be a leader on either).

Inside and outside of Florida, they’ll be no sunshine on the Florida primary until Tuesday night, when we’ll know all. For now: John McCain prays Crist is his savior, while Romney hopes he’s a false political prophet.