Michele Bachmann, for instance, quickly found herself cornered by a pledge she made last month in South Carolina that as president she'd guarantee that gasoline prices drop to $2 per gallon. As her challengers noted, factors affecting gas prices are too numerous for any such pledge to be taken seriously.

Just a few weeks ago, Rick Perry signed a pledge against gay marriage. In adding his name to the document authored by the National Organization for Marriage, Perry backtracked on his earlier pledge that he would leave the definition of marriage up to the states.

Ronald Reagan, the oft-sighted model of conservative governing, raised taxes 11 times during his presidency because it was the right thing for the nation.

Yet, all the contenders, except Huntsman, have signed Grover Norquist's Taxpayer Protection Pledge - the emphatic document, that bears the signatures of 270 Republicans in Congress, rigidly opposing tax hikes regardless of nature or need.

Huntsman's refusal to pledge makes good sense. "I think it diminishes the political discussion," he explains. "I think it jeopardizes your ability to lead once you get there."

The tax pledge led to a ludicrous exchange during last month's debate in Iowa in which Bachmann and Tim Pawlenty squabbled over a sliver of Minnesota tax history back in 2005, when he was governor and she was in the legislature. The measure in question had nothing to do with income taxes; it involved raising the tax on cigarettes. Yet there was Pawlenty, six years later, insisting that the cigarette hike was actually a "fee" rather than a "tax," which he nevertheless "regretted."

Democrats have their own pledges, such as the Social Security Protectors Pledge, which compels signatories to "oppose any cuts to Social Security benefits, including increasing the retirement age." Most House Democrats have signed.

It's one thing to take an unequivocal position on certain moral questions like the death penalty, but to apply the same absolutism to ever-changing economic and political issues is simply an abnegation of duty. One assumes that the public wants leaders who can think for themselves and, when necessary, actually modify their positions.

The late Tim Russert of NBC News was fond of asking candidates for high office to take pledges on all sorts of issues. In September 2007, Russert asked Barack Obama if he would "pledge" to remove all troops from Iraq by the end of his first term. The question, in its absoluteness, was unreasonable, and Obama wouldn't bite.

After offering that same pledge to other Democrats on stage, Russert asked Hillary Clinton: "Would you pledge to the American people that Iran will not develop a nuclear bomb while you are president?" She, too, declined to be bound by such a pledge - especially one that would forever be preserved on videotape in NBC's archives. Russert was a fine journalist, but his obsession with "pledges" marred his interviews.

Now, pledges have become more than devices employed by TV hosts -- they are increasingly the currency of political positioning. That's unfortunate, because at a time when Republicans and Democrats seem unable to agree on anything, pledges only make the situation more hopeless.

Taking a pledge is the political equivalent of holding one's breath and turning blue -- or, as the case may be, red.

(c) Peter Funt. This column was originally distributed by the Cagle Syndicate.