Iraq is mired in a civil war and American policy there has failed, Republican Sen. Gordon Smith told ABC News' George Stephanopoulos in an exclusive interview on ABC News' "This Week."
"Their civil war is theirs to answer," said Smith, when asked if American troops should begin withdrawing. "At the end of the day, I cannot, in good conscience, any longer support a policy which is, essentially, 'Let's hit them and then run back to the Green Zone.'"
The Iraqi Interior Ministry reported that 40 bodies -- many shot and tortured -- were found across Baghdad on Saturday, the result of the ongoing sectarian violence roiling Iraq.
I "do not support policies, nor should the American people support policies, that lead us down a path to defeat," Smith said. "And I believe that that's what we've been pursuing."
Smith first broke with his party over the issue of Iraq on Thursday night, when he delivered an emotional speech about the state of the war just before Congress recessed for the end of the year.
"I, for one, am at the end of my rope when it comes to supporting a policy that has our soldiers patrolling the same streets in the same way, being blown up by the same bombs day after day," said Smith before a mostly empty Senate chamber. "That is absurd. It may even be criminal. I cannot support that anymore."
At one time, Smith was a strong supporter of President Bush and his handling of the war. Just six months ago, he took to the floor of the Senate to argue against setting a timetable for withdrawal.
"As I have studied history, I have never found an instance whereby victory is won by announcing retreat," said Smith on June 21.
In 2004, Smith served as the chair of the Bush-Cheney reelection campaign in his home state of Oregon.
Smith explained his turnaround on the war by telling Stephanopoulos that conditions in Iraq have changed dramatically since he voted to authorize the use of force in Iraq in 2002.
"When you get to being policeman in a sectarian civil war, that is not what the American people enlisted for. That's not what I voted for," said Smith. "I voted for toppling a chief terrorist and tyrant, ridding him of weapons of mass destruction, but not for being target practice in the middle of a sectarian strife."
Sen. Joe Biden, D-Del., appearing with Smith on "This Week," said he believes Smith's shift marks a watershed moment in the debate over the war.
"No one but the president and the vice president is talking about if we're going to draw down American troops," said Biden. "Everyone is talking about how and when. That is a fundamental shift since Nov. 6."
Smith's change of heart comes on the heels of the release last week of the Iraq Study Group's final recommendations. The group's report called on President Bush to adopt 79 changes to his current Iraq strategy.
The day after the report's release, President Bush refused to commit to embracing all of the group's recommendations, but said he would give them careful study.
Even if Bush does adopt the proposals, Smith said he questions the ability for the president to fix the situation in Iraq.
"I don't know whether the president can put forward now a policy that will ultimately lead us to victory," Smith said. "I believe he has spent way too much political capital following the strategy that ultimately isn't designed for victory."