Updated

Former New York City Mayor Rudy Giuliani, Sen. John McCain, R-Ariz., and Sen. Hillary Clinton, D-N.Y., continue to be the most popular candidates in their respective party primaries, according to the latest FOX News poll. Hypothetical head-to-head matchups remain mostly unchanged from earlier in the year; Giuliani and McCain both lead Clinton, though the former first lady captures a double-digit edge over Vice President Dick Cheney.

With less than two years to go before the beginning of the presidential primaries, Sen. Clinton continues to be the clear choice among Democrats as their party's presidential nominee. The new FOX News poll finds Clinton receives the support of 43 percent of registered Democrats — outdistancing by about 30 points potential competitors such as former Vice President Al Gore (12 percent), former Sen. John Edwards (11 percent) and Mass. Sen. John Kerry (10 percent). These results are about the same as those in previous polling conducted last fall (September 2005).

Among Republican registered voters, Giuliani remains the front-runner and edges out McCain by 7 percentage points (29 percent to 22 percent). Other possible GOP contenders receive support in the single digits; former Congressman Newt Gingrich comes in at 8 percent and Tenn. Sen. Bill Frist is backed by 5 percent.

Direct comparisons to previous results are difficult due to changes in the Republican candidate list; Sec. of State Condoleezza Rice is no longer included as she adamantly maintains she will not run, while New York Gov. George Pataki (2 percent) and Nebraska Sen. Chuck Hagel (1 percent) have been added.

Opinion Dynamics Corporation conducted the national telephone poll of 900 registered voters for FOX News on March 14-15.

"Do Over" Presidential Runs

If John Kerry runs for president for a second time, 27 percent think he can win, which is just slightly higher than the 24 percent that think Al Gore could win if he puts his hat in the ring again.

McCain outdoes both Kerry and Gore: overall, 45 percent think he can win, as do half of Republicans.

More than four in 10 Democrats (43 percent) think McCain can win, which is more than think so about either Kerry (41 percent) or Gore (36 percent).

Current Standings in the Matchups

In general, the Republican candidates lead the Democrats by double-digits in the hypothetical races tested on the poll.

McCain leads Clinton by 11 percentage points (50 percent to 39 percent), and Kerry by 20 points (53 percent to 33 percent). McCain also tops Gore by 18 points (52 percent to 34 percent).

Similarly, Giuliani bests Clinton by 51 percent to 39 percent. These results have remained constant in polling conducted since November 2004.

When matched up against Cheney, Democrats pick up points and come out on top. Clinton bests Cheney by 13 points (50 percent to 37 percent), and Gore edges out Cheney by 12 points (48 percent to 36 percent).

Overall, the Republican candidates do a better job of keeping the support of their party faithful. McCain and Giuliani receive the backing of at least 80 percent of Republican voters, while in those same matchups Clinton is backed by just over 70 percent of Democrats and Kerry holds onto less than two-thirds. Democrats are more than twice as likely as Republicans to vote for the opposing party's candidate.

Among self-identified independent voters, Republicans have the advantage and receive about half of the vote in most of the matchups, with one exception — independents are more likely to support the Democrat when Cheney is the GOP candidate.

"Of course none of these results mean very much at this point," comments Opinion Dynamics Chairman John Gorman. "To actually win their respective party nominations, they are all going to have to campaign to the faithful first. On the Republican side, that means a Giuliani has to explain his pro-choice, pro-gay record to the religious wing of the Republican Party-probably not an easy sell. John McCain will be confronted with his varying views on the Bush administration-from harsh critic to enthusiastic supporter. There will be room for new candidates to emerge.

"On the Democratic side, it appears the first race will be to nominate the 'not-Clinton' and then the campaign will move to a referendum stage: Clinton versus not-Clinton. Will memories of the '90s be a plus or a minus by the late winter of 2008 when people first go to vote? It is likely after all of that the Democratic versus Republican standings, even if these are the candidates, will be changed a lot by the character of the primary races."

A Nice Person

Being strong on national security and the economy are important to voters in deciding their vote in the next presidential election.

Fully 84 percent of voters say it is "very important" for the next president to be strong on national security. While large majorities of Democrats, Republicans and independents agree, Republicans are almost 20 percentage points more likely to say that being strong on national security is very important.

An 83 percent majority says being strong on economic issues is very important — and here there is no partisan gap, as equal numbers of Republicans and Democrats agree.

Almost two-thirds of Americans (63 percent) say being strong on social issues will be very important to deciding their vote. Though this is a sharp drop when compared to national security and the economy, it is still a clear majority.

Democrats (71 percent) are much more likely than Republicans (54 percent) to say social issues will be very important.

One-third says it is very important to them that the next president be a "nice person."

And is the president a nice person? A plurality says George W. Bush is the nicest when up against McCain, Clinton and Gore. Asked to set aside politics, about 3 in 10 voters (29 percent) say Bush is the nicest person, 23 percent say McCain, 18 percent Clinton and 16 percent Gore.

A majority of Republicans (58 percent) pick Bush and another 23 percent McCain (with 4 percent each to Clinton and Gore).

Among Democrats, 32 percent say Clinton is the nicest, 29 percent Gore, 20 percent McCain and 7 percent Bush.

• PDF: Click here for full poll results.