A case can be made for looking at the national polls of each party's likely voters and at the polls of likely Iowa caucus attendees or New Hampshire primary voters. Other indicators are the size of each candidate's campaign war chest and which candidate has managed to sign up the most talent -- the latter a gauge of who insiders think has the best chance to win.
The best method is to take into account all of these factors, but we can't yet: We need more time, more Federal Election Commission fundraising reports, and more polling in Iowa and New Hampshire. As the candidates spend large amounts of quality time in those states, the survey results will become measures of how the campaign is evolving, not just measures of what voters thought before the race began.
A new Cook Political Report/RT Strategies poll, taken February 15-18, reinforces the view that Sen. Hillary Rodham Clinton's lead over the rest of the Democratic field is large and widening. The contest for the GOP nomination, meanwhile, remains close.
Among 390 Democratic voters and independents who lean Democratic, Clinton is well ahead with 42 percent, up 8 percentage points from November, the last time that Cook/RT Strategies asked about the 2008 race. Sen. Barack Obama runs second with 20 percent, just as he did in November.
Former Sen. John Edwards remains in third place, but at 16 percent he is 7 points higher than last time. New Mexico Gov. Bill Richardson is fourth with 5 percent. Bringing up the rear are Sen. Joseph Biden, retired Gen. Wesley Clark, former Iowa Gov. Tom Vilsack, former Sen. Mike Gravel, and Rep. Dennis Kucinich with 1 percent each, and Sen. Christopher Dodd, who is a bit under 1 percent. Twelve percent of Democratic respondents were either undecided or volunteered that they favored someone else.
Clinton's numbers have been rising in recent months, possibly because of Democrats' new bullishness -- since scoring big gains in the midterm elections -- about their chances in the 2008 elections and about her electability. Her favorable ratings have long been high among Democrats, but many party members have doubted her ability to win the White House if she were their nominee.
Since the midterms, though, Cook/RT Strategies polls in November and December have shown that 60 percent of Democrats consider Clinton as electable as any other Democrat, and only a third of respondents are worried that she might not be able to win a general election. Before the midterms, Democrats were evenly divided on that question.
On the Republican side, things are much murkier. Among the 320 Republicans and GOP-leaning independents surveyed, former New York City Mayor Rudy Giuliani remains first with 32 percent. Sen. John McCain runs second with 23 percent, former House Speaker Newt Gingrich is third with 13 percent, and former Massachusetts Gov. Mitt Romney is fourth with 10 percent.
In fifth place is former New York Gov. George Pataki with 4 percent, followed by Sen. Sam Brownback and Rep. Tom Tancredo with 2 percent each. Former Virginia Gov. Jim Gilmore, Sen. Chuck Hagel, former Arkansas Gov. Mike Huckabee, Rep. Duncan Hunter, and former Wisconsin Gov. Tommy Thompson all have 1 percent. Eight percent of Republican voters are undecided.
Although Giuliani leads in virtually every national poll and in many state polls, Gallup polling shows that three-quarters of Republicans do not know his positions on social and cultural issues. Gallup also found that 35 percent of Giuliani's supporters might defect if they knew his stands on such hot-button issues as abortion and gay rights. Such findings prompt most GOP insiders and independent experts to discount the former mayor's lead in the early polls.
For Democrats, the bottom line is whether Clinton can be stopped by any of her rivals. For Republicans, it's that this remains a very open contest, and the GOP nomination is unquestionably up for grabs.