Six weeks out from the Iowa caucuses, the presidential race looks more uncertain than ever. Only last week did the schedule of contests become certain: The day before Thanksgiving, New Hampshire Secretary of State Bill Gardner set the state's primary on Jan. 8, and the day before that, the state Supreme Court ruled that the Michigan primary can proceed on Jan. 15. Hillary Clinton and Rudy Giuliani continue to lead the competitions in national polls and in the large states, but on the Democratic side, there is a virtual three-way tie in Iowa, and on the Republican side, Mitt Romney leads in Iowa and New Hampshire. As for the general election, national polls show Democrats generally doing better than Republicans, but recent Rasmussen and Mason-Dixon polls show Hillary Clinton trailing in what was, in 2000 and 2004, the key state of Florida.

The political world was buzzing last week about the ABC News/Washington Post poll showing Barack Obama leading Clinton in Iowa. His lead was not statistically significant, and Iowa polls are problematic because of the difficulty of isolating the small number of caucus goers (only 5 percent of voters participated in the Democratic caucuses in 2004). A Clinton win in Iowa followed by another win in New Hampshire probably would clinch the nomination. But if Barack Obama wins in Iowa and gets a bounce in New Hampshire, it would be a two-way contest at least up through Feb. 5, by which time half the nation will have had a chance to vote. That might be true if John Edwards wins in Iowa, but New Hampshire has never much cottoned to Southern candidates; after a strong second in Iowa in 2004, Edwards finished a poor fourth in New Hampshire.

Democratic voters seem optimistic about winning in November, but they have a difficult judgment to make: About half the voters have favorable and unfavorable feelings toward Hillary Clinton, which means (A) she can win and (B) she can lose. That's not likely to change much because she's been in the national spotlight for 15 years. As general election candidates, Obama and Edwards, far less well-known, have more upside potential, but also, because they're far less tested, more downside potential, as well. If Democrats are concerned about electability, as they were in 2004, they have a tough judgment to make.

As for Republicans, the number of combinations of plausible results in the early contests rises into the dozens. Mike Huckabee is coming on strong in Iowa, threatening Mitt Romney's lead; John McCain is roughly tied with Rudy Giuliani for second place in New Hampshire; Giuliani and Romney are leading in Michigan; Fred Thompson seems to be narrowly behind Romney and Giuliani in South Carolina. These five candidates all have scenarios of varying plausibility showing them winning the nomination. The key question is whether the winners of Iowa and New Hampshire will get a bounce in the next contests. Bounces have been common, but not universal (Edwards 2004 and George W. Bush 2000 in New Hampshire). Will voters in Michigan and Florida be willing to subcontract their judgment to the voters in Iowa and New Hampshire who have seen more of the candidates? No one knows for sure.

Some Republican insiders are talking about the possibility that none of the candidates gets a majority of delegates. Presumably the nomination will be brokered, probably long before the convention, but not before the party goes through considerable turmoil. I think that's possible; unlikely things can happen (Florida 2000).

What about the general election? Consider two poll results: When the NBC News/Wall Street Journal poll asked voters which party they preferred to win the race for president, Democrats led 49 percent to 36 percent. When the FOX News poll asked which of two specific candidates would do the better job of protecting the country, Rudy Giuliani came out ahead of Hillary Clinton by 50 percent to 36 percent. Those numbers suggest to me that the range of possible outcomes in November 2008 is much wider than it was in November 2004.

What we have not seen yet is a debate between the two parties on ideas. The Democratic candidates have been busy pounding George W. Bush, who will not be on the ballot. The Republican candidates have been busy pounding Hillary Clinton, who may or may not be on the ballot. And candidates in each of the parties have gotten started pounding each other. These arguments are mostly about the past. We haven't heard much yet about the future.