By DAVID BENKOF

Ever since Sen. John Kerry, D-Mass., lost the 2004 presidential race in part because the Republicans labeled him a "flip-flopper," the claim that a candidate, especially for president, changes his positions too often and too easily has become a staple of American political discourse.

This election year, presumptive Democratic nominee Sen. Barack Obama (D-Ill.) has been repeatedly accused of flip-flopping in his foreign policies, especially with regard to Iraq and Iran. In July, Republican National Committee spokesman Alex Conant told the Associated Press, "There appears to be no issue that Barack Obama is not willing to reverse himself on for the sake of political expedience."

Well, there are lots of good reasons to vote against Obama, but flip-flopping isn't one of them. In fact, I want a president who won't hesitate to change his or her positions when the circumstances, the arguments, and even "political expedience" (read: public opinion) have changed.

Why on earth are we debating public policy issues in the first place if we don't want the people on the other side to change their minds? And why would they ever come around to our position if we will just label them a flip-flopper for doing so?

Our nation's greatest presidents have flip-flopped time and again, including on the most important issues facing the nation.

Abraham Lincoln ran for president in 1860 as a unionist, not an abolitionist. But over the course of the Civil War he became more and more convinced that slavery had to end. He signed the Emancipation Proclamation in 1863, and by the end of his life two years later, the only resolutions to the war he would accept had to include an end to slavery throughout the United States. Was Honest Abe a flip-flopper?

President Franklin Delano Roosevelt promised voters in his 1940 re-election campaign that he would not bring the nation into World War II. After Pearl Harbor was attacked the next year, would it have been a good idea for FDR to have to weigh the need to retaliate against Japan against the possibility of losing political support because of flip-flopping?

In 1967, California Gov. Ronald Reagan signed the most liberal abortion law in the nation. But as president, Reagan was reliably pro-life. Do the Republicans who are attacking Obama for flip-flopping wish their hero Reagan had stuck with his earlier cooperation with the pro-abortion movement?

It's one thing to criticize a president for raising taxes when he had announced in his nominating speech: "Read my lips: no new taxes." But the fear of today's ubiquitous charge of flip-flopping pressures candidates to dig in their heels on all their positions, and that's bad news for our democracy.

For example, some of the people attacking Obama accuse him of picking positions based on public opinion polls. While that would indeed be an unacceptable way for a president to make every decision, shouldn't public opinion at least be one factor in the mind of a democratically elected leader? I'd hate to live in a country where the leaders didn't care at all what the people wanted.

Not to mention, do we really want a major part of our political lingo to be a childish term like flip-flop that recalls equally juvenile turns of phrase like "teensy-weensy," "scribble scrabble," and "teeter-totter"? It's undignified - for everybody.

With Kerry, the accusation of flip-flopping resonated with 2004 voters largely because of the candidate's infamous clumsy comment about an Iraq reconstruction package: "I actually did vote for the $87 billion before I voted against it." And that line of attack thankfully worked for my fellow Republicans. But trying to take down every Democratic presidential candidate with the flip-flopper label makes about as much sense as trying to defeat Obama by accusing him of falsely claiming to have invented the Internet.

Actually, the flip-flop attack is worse, because we need presidents - and candidates - who feel free to change their minds, and their policies, when doing so is best for America.

David Benkof is a Ph.D. student in American Jewish history at NYU. davidbenkof@aol.com