March 5, 2008  | By John D. McKinnon

WASHINGTON -- The perception that the U.S. troop surge in Iraq has succeeded is changing some public views of the war, potentially blunting Democrats' political edge on the issue.

Americans continue to judge the nearly five-year-old U.S. invasion of Iraq as a mistake, by margins that have barely budged. But in a notable shift, public perceptions of the current U.S. military effort there "have become significantly more positive over the past several months," says a recent report from the nonpartisan Pew Research Center for the People and the Press. It shows that almost half of Americans think the war effort is going well, and that the U.S. should keep its troops there, at least for the time being. Other polls echo the trend to varying degrees.

The results suggest that -- barring another reversal in conditions -- Democrats' ability to use the war as a political weapon could be somewhat curtailed, particularly when the general-election campaign begins.

In part because of the shift in sentiment on the war, Democrats have turned more frequently to other issues -- particularly the weakening economy. That has been true both on the campaign trail and on Capitol Hill.

The recent change in public opinion appears pronounced among independent voters, and independents who see progress in Iraq are much more likely to support Republican John McCain, at least so far.

In the short run, the change also could be helping Hillary Clinton gain a measure of traction against Barack Obama, a persistent war critic who has scored by pointing to her vote in favor of authorizing the war.

The lessening of concerns over the war "is one thing that has enabled her to stave off the Obama onslaught" as long as she has, says Ruy Teixeira, a public-opinion expert at the Center for American Progress, a liberal think tank.

Bill Burton, a spokesman for Sen. Obama, said he "will not hesitate to do what is required to keep the American people safe as president, regardless of what the polls say."

In the most in-depth picture of the trend, the Pew report says that about half the public (48%) now says the Iraq war effort is going either very well or fairly well. That compares to a more than 2-1 majority who said it was going badly a year ago. Nearly half (47%) say the U.S. should keep its troops in Iraq until the situation there has stabilized -- roughly the same as those (49%) who favor bringing troops home as soon as possible. A year ago, 53% favored rapid withdrawal versus 42% who favored keeping the troops in Iraq.

Pollsters first noticed an uptick in public perceptions of the war in the fall. But the change in February "struck me as, 'Wow,'" said Andrew Kohut, the Pew Research Center director. The U.S. troop surge during 2007 sent 30,000 additional combat troops to Iraq to help quell growing violence. The last of the surge troops are scheduled to be withdrawn this summer.

To be sure, some other polls show less-dramatic change. And depending on how the question is asked, support for some form of troop withdrawal remains high.

Mr. Teixeira says that, on the whole, "people have the impression that things must have improved, but they haven't changed their verdict on the war or what to do about it."

Several polls reflect improvement in public perceptions. In a recent Gallup poll, 43% of respondents say the year-old U.S. troop surge has improved the situation. In July 2007, only 22% thought the surge was bringing improvement.

Mr. Kohut says there is no certainty that positive public opinion on Iraq won't plunge again. But in the fluctuation, he sees confirmation of a basic difference between Iraq and the Vietnam War of the 1960s and 1970s. "Opinions about Iraq have gone up and down in ways that opinion about Vietnam never did," he says.

Why the difference? "By the end of the [Vietnam War], the domino theory was so abstract it was hard for people to think of the negative consequences of South Vietnam going communist," he says. "On the other hand, the terrorist threat is more pressing and immediate."

Mr. Kohut thinks Americans want to see security gains from the U.S. involvement. Troop losses seem to matter less in public opinion than a positive trend on security, he adds.

The change in public attitudes comes at a time when it's increasingly likely that tens of thousands of U.S. troops will remain in Iraq for years to come, regardless of who is elected president. Advisers to the two Democrats say the candidates would begin withdrawing "combat" troops, but would keep significant numbers of "noncombat" troops in Iraq, and would largely abandon the counterinsurgency role that the U.S. currently is playing.

But the change in public attitude implies a potential political benefit for Sen. McCain, who supports both the war and the Bush administration strategy. The Pew findings show that independents who think the war is going well favor the Arizona Republican versus Sen. Obama by a large margin of 31 points, 58% versus 27%.

Recent polls suggest that, so far, Iraq isn't proving to be as much of an albatross around Sen. McCain's neck as some anticipated, says Karlyn Bowman of the conservative American Enterprise Institute.

Some polls also show the Democratic lead on handling Iraq has shrunk. In a Wall Street Journal/NBC News poll, it was six percentage points in January compared with 15 points last July.