Could Democrats give Obama trouble in 2012? War in Afghanistan is key.

As Democratic pollster Stan Greenberg was leaving a Monitor breakfast last week, he was asked about the possibility that President Obama might face a Democratic primary challenge in 2012.

Mr. Greenberg’s two-word answer: “Watch Afghanistan.”

Indeed, of all the issues on Mr. Obama’s plate, the war in Afghanistan is his biggest area of political vulnerability among his own Democratic base. A Quinnipiac poll released last week showed that, for the first time, overall support for US involvement in Afghanistan has gone negative. Forty-four percent of the American public now supports the US role there, with 50 percent against. In September, 49 percent supported US involvement, with 41 percent against, the nonpartisan Quinnipiac poll found.

But beneath that top line sit dangerous numbers about Democratic opinion. Among Obama’s own party, only 33 percent say the US is doing the right thing in Afghanistan; 62 percent say it’s not. Among independents, a group Obama must woo to win reelection, US involvement in Afghanistan has only 40 percent support; 54 percent oppose. Republicans are the only group favoring the US commitment. They back the war 64-31.

And these numbers were taken before last weekend’s NATO summit in Lisbon, where talk turned to a goal of 2014 for transferring the security of Afghanistan to the Afghans. The earlier benchmark – that in July 2011 the US will begin to withdraw its troops from Afghanistan – is still in place, but with wide latitude to adapt as the security situation warrants. Antiwar voters will hardly be happy with all the talk of 2014.

“In terms of support for the war, Republicans are the only thing he’s got,” says Peter Brown, assistant director of the Quinnipiac University Polling Institute in Hamden, Conn.

Even though support for the Afghan war doesn’t win Obama Republican votes in a general election, it does buy him the backing of Congress on war-funding. “It’s tough to fight a war when only a quarter of the population thinks it’s a good idea,” which is where Obama would be if he lost the Republicans, Mr. Brown notes.

“My sense is that Obama really is sort of in a box on this, and everyone is hoping that" the scheduled troop withdrawal in 2011 and 2012 "will be fairly smooth,” says Democratic strategist Peter Fenn. “I guess what I’m saying is, if it’s an issue for Obama, it will be bad. These Republicans are not going to vote for him anyway.”

So in political terms, Obama first needs to worry about the possibility of a primary challenge from the antiwar left. It would be difficult for anyone to beat him in the primaries, but he could be severely wounded, as President Johnson was over Vietnam heading into the 1968 presidential election – a race he ultimately quit. So far, former Democratic National Committee chair Howard Dean and soon-to-be ex-Sen. Russ Feingold (D) of Wisconsin have both insisted they won’t challenge Obama. Rep. Dennis Kucinich (D) of Ohio may well run again, though he would not be considered a serious threat. Still, his antiwar message could hurt Obama. Greenberg, the Democratic pollster, didn’t offer up any names.

Even if Obama heads into November 2012 unscathed by the primaries, a Democratic base demoralized over Afghanistan could pose a big problem. Obama is counting on ramping up his 2008 electorate again, and if enthusiasm for turning out isn’t there, he will have a hard time prevailing.

“Liberals," says Mr. Fenn "can be notorious for sitting on their hands.”

Another recent poll on Afghanistan policy showed a slightly more positive result for Obama, but the trend is still moving away from his position. A Wall Street Journal/NBC News poll taken Nov. 11-15 mentioned Obama by name in asking about his Afghan war policy, and found 48 percent approval versus 41 percent disapproval. That’s a decline in approval from March, when 53 percent approved and 35 percent disapproved.