The crash of a transport helicopter that killed 31 marines in Iraq - marking the deadliest day for US forces there since the invasion - is putting new weight on Sunday's elections as a potentially critical turning point not only for Iraqis, but for Americans, too. Depending on the outcome, the vote this weekend could dramatically bolster support for the war - providing a sense of hope and progress after weeks of growing public disillusionment - or it could intensify demands for the withdrawal of US troops.
President Bush sought once again to steel public support for the Iraq mission Wednesday, issuing a statement on the helicopter crash and holding a public news conference.
At the press conference, Bush acknowledged that the loss of US marines is "very discouraging to the American people," and he stressed that the US "will complete the mission [in Iraq] as quickly as possible." But he also cast the upcoming elections as "a grand moment for those who believe in freedom."
The incident came amid signs that Americans are increasingly souring on Iraq, with a majority now saying the invasion was a mistake. That sentiment has been reflected in Congress, where Democrats - including some from states that Mr. Bush carried in November - spent the past few days sharply questioning Condoleezza Rice, before confirming her as secretary of State, over mistakes made in the run-up to the Iraq war.
Some members of Congress also expressed concern about how their constituents would react to the Bush administration's request for an additional $80 billion in emergency spending for Iraq and Afghanistan.
To some extent, Bush's growing challenge in rallying public support for the war could be seen in last week's inaugural speech, which offered what was intended to be an idealistic case for the administration's Iraq policy - casting the spread of democracy as the ultimate antidote to terrorism - but which also never mentioned Iraq by name. Polls taken in the wake of the speech showed it had little impact on public views on the war.
Still, the upcoming elections could change all that - either vindicating Bush's policies, or else making success there look unattainable.
"As far as the war is concerned, I think Jan 30 is the ultimate tipping point," says independent pollster John Zogby.
Certainly, public opinion on Iraq has grown markedly more negative in recent weeks, with 52 percent of Americans now saying the war was not worth it, as opposed to 46 percent who think it was, according the most recent Gallup poll.
But the trend is less clear when it comes to whether Americans think the US should withdraw its troops, with 46 percent wanting to withdraw some or all troops, while 50 percent want to keep troop levels where they are or send more.
Polls also show that, despite Bush's hopeful rhetoric, Americans have relatively low expectations surrounding this weekend's elections. A recent Associated Press poll found that 53 percent think it's unlikely that a stable, democratic Iraq will be established.
And, significantly, the public currently does not see the elections as likely to provide the US with an opportunity to begin withdrawing troops. According to Gallup, only 15 percent believe the elections will allow the US to withdraw troops within the next few months.
Still, Mr. Zogby believes that many Americans will want to see an indication of an endpoint to the occupation, whether or not the elections are seen as a success, because Sunday's vote will represent to many a marker in the process of handing power back to the Iraqis.
"Americans like their wars to be short," he says. "They are going to want to see an exit strategy."
Calls for an exit strategy are already cropping up among some observers and lawmakers - who suggest that a timetable for US withdrawal could have a beneficial effect on the situation in Iraq, because resentment over the US presence is fueling the insurgency faster than American troops can beat it back.
Rep. Martin Meehan (D) of Massachusetts, who recently returned from a visit to Iraq, this week offered a detailed proposal to draw down US troops over the next 12 to 18 months. While the upcoming elections represent a positive development, he says, they're unlikely to stem the violence.
"I think Americans want to see light at the end of the tunnel," he says.
Other experts say a timetable for US withdrawal would simply encourage the insurgents in Iraq, and undermine the new government. Moreover, they say Americans understand the importance of the mission and are likely to remain patient.
The public's unhappiness has not so far translated to a clear desire to pull out before Iraq is stabilized - and that the elections may not change that. Americans are "very responsive to the idea that that would be dangerous," says Steven Kull, director of the Program on International Policy Attitudes at the University of Maryland.
"Before they would actually turn toward wanting to withdraw, there would have to be some kind of trigger," he says - something along the lines of a prominent American leader convincing the public that pulling out is not only a viable option, but that it would not leave Iraq a breeding ground for future terrorists.
One factor that experts agree would lead to a strong demand to pull out would be if the newly elected Iraqi government asked the US to leave - though there's substantial disagreement on how likely that may be. Mr. Meehan sees it as almost inevitable, saying that politically, no Iraqi leader is going to want to be seen as pro-occupation. But others argue that the new Iraqi government will likely recognize that its survival depends on the ongoing security provided by US troops.