The last time a Republican candidate for president defeated an incumbent Democrat running for reelection, the primary returns were a lopsided affair. Ronald Reagan won convincingly in New Hampshire and South Carolina (after George H.W. Bush took Iowa) and went on to capture nearly 60 percent of the GOP vote in a three-candidate field.

Mr. Bush landed relatively few verbal blows of consequence — his infamous "voodoo economics" line to describe Mr. Reagan's supply-side philosophy being the exception. In 1980, the party was largely unified, and Rep. John B. Anderson's decision to run as an independent had little effect on the outcome as Jimmy Carter lost badly in November.

Since then, the party has embraced unity almost as a religious belief. When the GOP establishment chooses its nominee early — as was the case withGeorge W. Bushin 2000 — confidence is high, and the results have generally proven favorable.

That shared history may explain the sense of panic that seems to have beset Republicans, particularly those in the Washington establishment, by the political gyrations of this year's race for the White House. Newt Gingrich's victory in South Carolina has clearly forced a political party that prefers to see election outcomes follow a script deal with high-wire improvisation.

Mr. Gingrich can now consider himself a front-runner, but the local fishmonger's inventory has a longer shelf life. On the defensive in the week leading up to South Carolina, Mitt Romney has upped his attacks on the former House speaker in recent days — on matters ranging from his work as a consultant to his general goofiness — and they are likely to have an impact before Florida votes on Jan. 31. Polls initially showed a Gingrich surge there after the South Carolina vote, but they now suggest a dead heat.

Nor is it quite time to dismiss Rick Santorum whose apparent victory in the Iowa caucuses has raised his delegate count to 13, just 10 behind Mr. Gingrich and 6 from Mr. Romney. The spending of Super PACs is also adding to the political volatility of what could prove a landmark 2012 race. Ron Paul and his highly devoted followers are another wild-card to be considered.

But here's a news flash for the Republican faithful who are beginning to fret that all this uncertainty — and more pointed debate — has begun to diminish their chances this November, particularly as President Barack Obama's standing with voters improves in the polls: This messy business of primary season is democracy in action. Do not despair.

There is a term for a political party that is so disorganized that its candidates attack each other ruthlessly and unlikely candidates eke out unexpected victories and eventually win nominations. We call it the Democratic Party. From Carter to Clinton to Obama, the candidates often survived underdog status and tough primary challenges before their day in the sun.

Bill Clinton's experience in 1992 may inform the Republicans best. His early losses in Iowa and New Hampshire to Tom Harkin and Paul Tsongas might have proven devastating, particularly in light of the allegations of Gennifer Flowers. But he bounced back with a strong showing on Super Tuesday and defeated President Bush in the fall.

Democrats don't generally pull their rhetorical punches in primaries. But it doesn't mean the eventual winner has been weakened by the blows. Often, it means the candidate has gained an opportunity to refute criticism against him, potentially insulating him from similar attacks in the general election. Even a disadvantage in fundraising can be made up fast — just ask Mr. Gingrich and his $10 million benefactors, the Adelson family of Nevada.

The reality is that less than 5 percent of Republicans have made a choice so far. No election should be determined by such a small sample. The lack of a clear victor at this stage should motivate voters and encourage further debate and reflection. What's wrong with that?

Conventional wisdom is that undecided voters often don't make up their minds until days before an election. So no matter how long the primary drags on, there will be plenty of time for the GOP nominee to make his case to the electorate — even if the unthinkable happens and the race is too close to call when the Republican convention convenes Aug. 27 in Tampa.

So don't panic, Republicans. This election year looks to be a little different from what you've seen in the last few decades. Anything can happen. As long as unemployment remains high and economic growth low, Mr. Obama's support will be shaky, too.