Analysis: Obama's centrist emphasis gives GOP ammo

Four years ago, Republicans branded as a "flip-flop" even the slightest rhetorical or policy change by John Kerry and sent huge replicas of the casual sandals to bob around the Massachusetts Democrat's events, feeding an image of him as a wishy-washy panderer.

Fair or not, Kerry never recovered and lost to President Bush.

It's now the Republican weapon of choice against Obama.

The Illinois senator has excited many with the notion that he is a new, transcendent type of politician. But he is giving the GOP effort ammunition and endangering his "Change We Can Believe In" motto with several shifts to the center, most recently on the Iraq war, his campaign's defining issue.

General election campaigns invariably find candidates fine-tuning what they said during primaries.

When politicians compete against others in their party, they must appeal to the most partisan, who tend to make up the majority of enthusiastic voters at that stage. But general elections require a broader appeal, particularly to the vast center of the nation's electorate.

So it's not uncommon as spring fades and November approaches to see candidates de-emphasize or even cast off some of their most extreme positions in favor of policy more palatable to the middle. They mostly do it quietly, or try to anyway.

And though there can sometimes be criticism about shifting positions, voters usually forgive and forget.

For one thing, a willingness to hone policy, add nuance or even change one's mind--especially when new information comes to light--is not in itself a bad quality in a leader. For another, those partisans who supported a candidate in the primaries are not likely to switch parties and back the other candidate. Often the worst that can happen is they stay home on Election Day. Politicians are usually willing to risk that for the chance to court the center.