Some of the races in the 2006 congressional elections may still be undecided, but presidential candidates are already jockeying for 2008.
Sen. John McCain, R-Ariz., the apparent Republican frontrunner, is moving closer to a formal candidacy, even though he says a formal decision won't be made until he talks it over with his family during the Christmas holidays.
"Are we doing the things organizationally and legally that need to be done to prepare for it? Yes," he said on NBC's "Meet the Press."
McCain is already scouting office space in the northern Virginia suburbs of Washington for his campaign headquarters.
Sen. Hillary Clinton, D-N.Y., who is McCain's counterpart as the unofficial frontrunner in the Democratic Party, says she hasn't made a formal decision yet, either.
But on ABC's "This Week," one of her colleagues said he had.
"I still plan on running," said Sen. Joseph R. Biden Jr., D-Del., whose 1988 presidential bid floundered after he was discovered to have lifted significant parts of his stump speech from British politician Neil Kinnock.
"For these candidates, they better already be running or at least be in the starting blocks if they are going to have a chance," said Mark Halperin, ABC News' political director and co-author of "The Way to Win: Taking the White House in 2008."
The 2008 presidential campaign promises to be a wide-open affair. It will be the first presidential election since 1928, when Herbert Hoover defeated New York Gov. Al Smith, in which a sitting president or vice president will not be a candidate.
"For a lot of these would-be candidates, this is the most open presidential race of their lifetime," said Halperin. "It may be their last chance to run for the office."
Already, two dark-horse candidates have formally announced their candidacies -- outgoing Gov. Tom Vilsack, D-Iowa, and Rep. Duncan Hunter, R-Calif., chairman of the House Armed Services Committee.
Two other Democrats have said they are passing up long-shot candidacies -- Sen. Russ Feingold, D-Wis., who announced his decision this afternoon, and Mark Warner, the former Virginia governor.
Handicappers rate McCain and Clinton as the early favorites based on their name-recognition, fundraising and organizational strengths.
Unlike Clinton, who had to run for re-election this year, McCain spent this campaign season crisscrossing the country for Republican candidates, building up alliances he could use in a presidential race. He attended 346 events that generated more than $10.5 million. In addition, he gave nearly $1.5 million of his own political funds to federal, state and county parties.
"Did a lot of good, didn't it?" McCain quipped on "Meet the Press."
Other Republicans who have been laying the groundwork for possible presidential bids include Massachusetts Gov. Mitt Romney, Senate Majority Leader Bill Frist, Arkansas Gov. Mike Huckabee, Kansas Sen. Sam Brownback and former New York City Mayor Rudoph Giuliani.
Potential Democratic contenders include former North Carolina Sen. John Edwards, who was the 2004 vice-presidential nominee, New Mexico Gov. Bill Richardson and Sens. Evan Bayh, Christopher Dodd, Barack Obama and John Kerry, the party's 2004 presidential nominee.