If Hillary Clinton is such a shoo-in for her party’s 2008 presidential nomination, then a new Florida poll is something for Democrats to worry about.

More than 30 months before the 2008 election, Sen. Clinton can’t get more than 50 percent of the vote when matched against two unknown Republican candidates?

And, given Florida’s key role in the Electoral College, the new survey will almost certainly provide more fodder for one of the most popular parlor games in New York and Washington these days – “Can Hillary Win?”

That’s because there is almost a consensus developing among many of the Democrats who spend their waking hours thinking about the next election that she is very likely to be their 2008 presidential nominee.

Many Democrats are happy about this – especially feminists and, except for the really left-wing types who think she doesn’t genuflect to their causes enough – party liberals.

But among those who see themselves as Democratic centrists, especially with roots in the Sun Belt, there is worry her candidacy might be as unsuccessful in November as were those of George McGovern, Walter Mondale and Michael Dukakis.

Even though Sen. Clinton has sought to recast herself as a political moderate, the former first lady still has a serious problem in “red state America,” as the new poll results show.

Florida is the most important “red state” and probably the most likely one in the Sun Belt for a Democrat to win in a successful presidential campaign. Remember, Bill Clinton carried it in 1996, and Al Gore essentially tied it in 2000.

A number of public opinion polls have tested Sen. Clinton’s strength, both nationally and in some states, against former New York Mayor Rudy Giuliani and Sen. John McCain of Arizona. They are the two potential candidates who lead Republican trial heats, and she generally trails both of them.

Both Giuliani and McCain, like the former first lady, enjoy almost universal name recognition. The results of the polls pitting them against each other reflect public opinion based on roughly equal knowledge of the candidates.

In Quinnipiac University’s May Florida survey, for instance, McCain led her 48-42 percent and Giuliani was ahead 49-42 percent.

But neither man’s record reflects the views and values of the GOP conservative base, which generally holds sway over the presidential nominating contest.

However, Quinnipiac also matched up Sen. Clinton against two other 2008 potential Republican presidential aspirants, Sen. George Allen of Virginia and Gov. Mitt Romney of Massachusetts. She defeated Allen 46-40 in a survey taken in April and Romney 50-39 percent in a May poll.

Both Romney and Allen are little known outside their own states, and the survey question that asked voters to decide between them and Sen. Clinton supplied only their party label and current or last office held.

There is an oft-quoted axiom in politics that when a well-known candidate is matched against an unknown in a poll far before an election, the better-known is probably at or close to their maximum support level.

That’s because of the (generally, but not always true) assumption that such trial heats are almost exclusively about the well-known candidate who is unlikely to do better once the opponent gains more visibility.

The significance of Sen. Clinton not getting a majority, even against two unknowns, is in the eye of the beholder.

But Democratic centrists who think she would take the party down with her if she were the nominee will likely give voice to the results.

As for Republicans, it will probably reinforce the belief among most that although Sen. Clinton would rally the Democratic base, she would have difficulty winning a two-candidate general election.

Of course, Sen. Clinton’s supporters will accurately point out that she does not need Florida to win the White House. All she has to do is carry the same states John Kerry did in 2004 and add Ohio.

But over the past three presidential elections, the Democratic vote percentage in Ohio has averaged only 2 percent more than in Florida.

That’s why this preliminary data about Sen. Clinton’s popularity against two relative unknowns matter.