MIAMI — Before Hillary Rodham Clinton raked in more than $300,000 at a private South Florida fundraiser last week, the junior Democratic senator from New York did something that presidential candidates usually avoid in the Sunshine State — at least until the general election. She spent two hours in front of news cameras publicly campaigning for votes.

Republican contender Mitt Romney also made a bit of Florida history last week by including the state in the first major run of television advertising aired by any of the 2008 White House hopefuls. Other candidates from both parties are lavishing the state with attention, in a dramatic expansion of its traditional role as little more than an automated teller machine for party primary candidates seeking the fourth-largest state’s tempting trove of campaign cash while ignoring its nominating contest.

The difference this year is that Florida’s political leaders are dead serious about scheduling the state’s nomination balloting within a week after New Hampshire’s first-in-the-nation primary. Charlie Crist, Florida’s new GOP governor, is working closely with the Republican legislature to move the contest up from its meaninglessly late spot on the calendar in March, despite threats of punishment from national leaders in both parties.

Even though the 2008 presidential campaign is well under way, several states are still scrambling to set early primary dates, making it tough for candidates to know for sure what the nomination schedule will look like in less than a year. But increasingly it appears that Florida is poised to host the most influential contest of them all — one that would confer more convention delegates than the combined total of the currently scheduled first wave of primaries and caucuses in Iowa, Nevada, New Hampshire and South Carolina.

While other large states, such as California, Illinois, New Jersey and New York, are contemplating earlier-than-ever dates for their primaries, campaign operatives in both parties are calculating that Florida offers the most competitive environment for the entire field of candidates, featuring no home-state advantage for any candidate and the most crucial proving ground for a general election that is again likely to see the state play a pivotal role.

For evidence of Florida’s emerging dominance, look no further than the candidates’ itineraries; appearances in the state or announcements of future trips have become almost daily news items in recent weeks. Florida’s Democratic and Republican political players are being courted early as never before, prompting a flurry of news releases from candidates announcing their latest trophy hire or endorsement.

The Florida press corps, one of the most competitive in the country, is champing at the bit for a presidential primary that really matters. Clinton’s trip garnered plentiful coverage on local television and in the three major daily newspapers of the region. And the national media are watching. Under the headline “Florida: ‘Sunshine’ Will Rise Again,” the Chicago Tribune recently asserted that it will be “the biggest state that is truly competitive in the premier party trials.”

Apart from how Florida’s big delegation could sway the outcome of a party convention, the state stands alone among the likely first stage of primary states as a key player in the general election. “It’s hard to imagine a Republican being president without carrying Florida,” Romney, the former Massachusetts governor, said while in the state on his first post-announcement campaign swing.

Florida lawmakers are counting on the state’s significance in the general election to thwart any attempts by national party leaders to punish them for moving the primary date. Party bosses on both sides have been threatened with sanctions, such as refusing to seat all or part of the state’s convention delegation. But such an extreme step would risk alienating the very operatives and donors that both parties will be heavily courting next November.

National party leaders, eager to protect the traditional calendar, have for years batted away attempts by other states to become part of the pivotal early action. But determined Florida politicos, such as Crist, say they will not be bullied this time. And if they’re successful, their state could end up crowning one or both nominees, especially if the smaller kickoff states advance a crowded field. Even if California gets into the mix, campaign professionals say it’s so big and unwieldy that only the extremely well-financed would be able to compete in what would be little more than a television advertising campaign.

Florida’s broad mix of voting groups, which are more representative of the rest of the country than those of other major states eyeing early primaries, would give the winner here a powerful argument for electability. And of course it sure doesn’t hurt that the state’s average high temperature in February is 70 degrees, compared with the below-freezing averages in Iowa and New Hampshire.

Contributing Editor Craig Crawford is a news analyst for NBC, MSNBC and CNBC. He can be reached at ccrawford@cq.com.