The political showdown over the war in Iraq between President Bush and the Democratic-controlled Congress has become a defining issue in the early stages of the 2008 U.S. presidential election campaign.  VOA national correspondent Jim Malone reports from Washington. 

The differing views on Iraq between the president and congressional Democrats are also being reflected daily on the presidential campaign trail.

The Democratic presidential contenders support various troop withdrawal proposals that would force a redeployment of U.S. forces out of Iraq next year.

(From left) Democratic Senators Harry Reid, Chuck Schumer and Joe Biden after Iraq vote

Anti-war rhetoric dominated the speeches of several Democratic candidates who recently addressed a convention of construction union workers in Washington.

Among them was Delaware Senator Joe Biden.

"Ladies and gentlemen, this war must end," said Senator Biden.  "This war must end and it must end soon!"

At times, Democrats compete with each other to see which candidate has opposed the war the longest.

Democratic presidential hopeful US Sen. Barack Obama in Oakland, California

"I am proud of the fact that in 2002, I stood up and said this is a bad idea, that this is a war that should not have been authorized and should not have been waged," said Illinois Senator Barack Obama.

Obama is running second in the polls to New York Senator Hillary Clinton.  Clinton supports a deadline for the withdrawal of U.S. troops from Iraq but so far has refused to say her vote authorizing the war in 2002 was a mistake, unlike some of her Democratic rivals.

Stuart Rothenberg publishes a non-partisan political newsletter in Washington.

"There is an effort on the Democratic side to show that each of these candidates was the most critical of the president, or in some cases that they were the earliest critics of the president, or that they have been the most vociferous critics of the president," he said.

There is much more support for President Bush's war strategy among the Republican presidential contenders.

The most aggressive supporter of the new troop surge strategy is Arizona Senator John McCain, a fierce critic of Democratic efforts to set a deadline for troop withdrawal.

Senator John McCain (R)

"We are making progress and we can succeed with this new strategy," said Senator McCain.  "To hamstring and to announce that we are leaving is one of the most shameful things I have ever seen."

McCain trails former New York City Mayor Rudy Giuliani in the latest opinion polls.  Former Massachusetts Governor Mitt Romney is third among active candidates, though former Tennessee Senator Fred Thompson also scores well among Republican voters.  Thompson says he is considering joining the race later this year.

Another potential contender is Nebraska Senator Chuck Hagel.  Hagel has emerged as perhaps the top Republican critic of the Bush strategy on Iraq.

Sen. Chuck Hagel speaks at a news conference regarding his political future in Omaha, Nebraska, 12 March 2007

"This idea that somehow you do not support the troops if you do not continue, in a lemming like way, to accept whatever this administration's policy is, that is what is wrong," said Senator Hagel.

Hagel is one of only two Republican Senators to support a Democratic plan to set a troop withdrawal deadline as part of an emergency spending bill for military operations in Iraq and Afghanistan.

President Bush says he will veto the bill if it contains the withdrawal deadlines, which have been approved by narrow margins in both the House and Senate.

Political experts question how much success Senator Hagel would have as a war critic in a Republican presidential field dominated by supporters of the current military strategy in Iraq.

John Fortier is a political analyst at the American Enterprise Institute in Washington.

"The three big [Republican] candidates are very supportive of Bush and the surge and the war," he explained.  "He [Hagel] would look a little bit different, but even if the war is unpopular generally, which it is, it is still relatively popular in Republican circles and I am not sure that he is going to get that much traction in this field."

Iraq is by no means the only issue in the early stage of the campaign.  Candidates from both parties spend a lot of time talking about their views on health care, immigration, the threat of terrorism and U.S. foreign policy in general.