More voters say the situation in Iraq will be extremely important in deciding their 2008 vote for president than any other issue, including terrorism, health care and the economy, according to the latest FOX News poll. In addition, more people cite disagreement on Iraq as a deal-breaker in their vote than the issues of abortion and gun control.

Opinion Dynamics Corp. conducted the national telephone poll of 900 registered voters for FOX News from May 15 to May 16. The poll has a 3-point error margin.

Over half of Americans (52 percent) say the issue of Iraq will be an extremely important factor in their vote for president, and when those saying it will be very important are considered, an overwhelming 89 percent majority says Iraq will be important in their decision.

"Iraq is likely to grow in importance as the debate between the administration and Congress continues," says Opinion Dynamics Chairman John Gorman. "With even some Republicans talking about ‘progress by September,’ voters are going to be looking for candidates to show them a clear path."

• Click here to see full results of the poll.

FOX News Poll: Voters Focus on Iraq, Terrorism, Health Care

The next most important issue for voters is terrorism at 43 percent extremely important, followed by health care at 41 percent and the economy at 37 percent extremely important.

Some issues are non-negotiable. If they disagree on the issue of Iraq, half of voters (52 percent) say they would not be able to vote for that candidate, even if they like the candidate and agree on most other issues. No other issue is a deal-breaker for as many voters.

Nearly one of three (32 percent) say they would not be able to vote for a candidate with whom they disagree on the issue of abortion; among Republicans, that increases to 38 percent.

On the future of Iraq, the poll shows that more voters support setting a specific deadline for withdrawing U.S. troops (39 percent) over the options of setting benchmarks for Iraq to meet to continue receiving help from the U.S. without a withdrawal deadline (32 percent) and giving the troop surge time to work before setting any deadlines (24 percent).

When choosing between just two options, by a margin of 46 percent to 34 percent, more Americans say it is more important for U.S. troops to get out of Iraq than it is for the United States to succeed and establish a stable Iraq.

Republicans (57 percent) are significantly more likely than Democrats (19 percent) to say it is more important to succeed in Iraq than to withdraw.

Views on the future of Iraq are decidedly mixed: About a third of Americans feel the United States can still be successful in Iraq (33 percent), while almost as many think the U.S. is losing, but has not lost the war (31 percent). Just over one in four — 26 percent — believe the U.S. has lost the war.

Democrats (41 percent) are fives times as likely as Republicans (8 percent) to believe the war is lost, and Republicans (57 percent) are nearly four times as likely as Democrats (15 percent) to believe the United States can still be successful.

Overall, by more than two-to-one, Americans see Senate Majority Leader Harry Reid’s recent statement that the Iraq war is lost as unacceptable while U.S. troops are still in the field fighting (65 percent unacceptable, 29 percent acceptable).