Forecast for Iowa: Cold and Bitter

Now that the last round of presidential debates in Iowa has concluded with no knockouts, the candidates will move to the decisive phase of the campaign—the negative one. The first-in-the-nation Iowa caucuses are only a couple of weeks away, on January 3, and the races on both the Democratic and Republican sides are increasingly tight. Many voters are bouncing from one candidate to another, almost day to day, as they assess their choices.

Campaign signs, like these outside the final debate site, are Iowa's quadrennial winter crop.

In this volatile atmosphere, Democrat Barack Obama has closed to a tie with longtime front-runner Hillary Clinton in Iowa and, more surprising, former Arkansas Gov. Mike Huckabee has come from nowhere to sail past longtime Iowa leader Mitt Romney for the GOP.

The political pros say now is the time for the negative stuff, in Iowa and beyond. Romney, the former governor of Massachusetts, has started running a TV ad critical of Huckabee for being too lenient on illegal immigration. Huckabee had some tart remarks about Romney's Mormon religion. In New Hampshire, William Shaheen, a key supporter of Clinton, said Obama's admission that he used marijuana and cocaine as an adolescent would hurt him in the general election if he were nominated. Obama supporters saw this as a low blow, and both Shaheen and Clinton apologized. But Shaheen's points were still widely spread in the news media and on the gossip circuit.

All this marks an abrupt shift from the largely positive tone of the campaign so far, symbolized by Oprah Winfrey's recent appearances for Obama in Iowa, South Carolina, and New Hampshire. The internationally famous talk-show host didn't criticize others in the race; instead, she gushed that Obama would bring a new, more uplifting approach to leadership and break away from Washington's tired formulas for rancor and stalemate.

As winter deepens, that positive tone will seem increasingly quaint.