Barack Obama’s approval rating is hovering around 40 percent, falling as low as 38 percent in a recent Gallup survey and 39 percent in the latest McClatchey-Marist poll.

That’s bad. But it gets worse.

The new ABC News/Washington Post poll says that 55 percent of Americans now expect that whoever wins the Republican presidential nomination in 2012 to take the presidency. Only 37 percent believe Obama will win.

That’s really bad. And the numbers from the battleground states are even more unsettling, A new Quinnipiac survey of Florida voters finds that only 39 percent approve of Obama’s handling of the presidency, while 57 percent disapprove. Only 41 percent of those surveyed say they think the president should be reelected.

Polls are transitory. The president’s numbers can and probably will improve, especially if he stays focused on the message he has been delivering in recent days: invest in job creation, establish fairer tax policies that make the rich pay their share, defend Social Security, Medicare and Medicaid.

But his decision to submit free-deals with South Korea, Columbia and Panama to Congress — deals that are opposed by organized labor and that even Obama-friendly analysts say threaten U.S. manufacturing jobs — could undo any progress for the president, especially in battleground states such as Ohio, Michigan, Pennsylvania, Indiana and Wisconsin. Congressman Mike Michaud, D-Maine, says flatly that Obama’s move is not going to go over well with working people. "Does (Obama) want to create jobs at home with the American Jobs Act, or does he want to offshore them to places like South Korea? At a time of nine percent unemployment, I know what my constituents would prefer," says Michaud. “There’s something wrong with this picture and the American people see right through it."

So what happens if the president doesn’t get traction? What if his numbers stay in the doldrums, or only improve marginally? What if working families turn against him in numbers that spell real trouble in swing states? Then the man who had such lengthy coattails in 2008 could become a burden for down-ballot Democrats in 2012. Just as anti-Obama sentiments on the right pulled voters to the polls in 2010, while a waning of enthusiasm for the president on the left depressed Democratic turnout that year, 2012 could see a pattern where Democrats lose not just the presidency but the Senate, the House and key state contests across the country.

That doomsday scenario has a lot of Democrats in Washington scared. But not all of them accept that 2012 has to be an either/or year where Democrats either win everything or lose everything.

Congressman Peter DeFazio, the Oregon populist who rarely minces words when it comes to policy and political calculations, is arguing that “Democrats are all going to have to distinguish themselves from the president.”

DeFazio has never made a secret of his frustration with the president’s compromises on economic issues. The Oregon progressive broke with his caucus to oppose the 2009 stimulus bill because he said it contained to little investment in infrastrure and real job creation. He was right. But that did not please the president, who told the congressman at a House Democratic Caucus meeting that year: “Don’t think we’re not keeping score, brother.”

DeFazio is fine with that. He has continued to put distance between himself and the president. After Obama compromised with “Tea Party” Republicans on budget and deficit issues this summer, the congressman said of the president: “Fight? I don’t think it’s a word in his vocabulary.”

DeFazio also said that, against a “respectable” Republican foe, Obama’s “going to have a very tough time getting re-elected.”

So if Obama goes down, do Democrats, as well?

Progressives and populists have begun to argue that Democratic congressional candidates can and should run on issues that work for them—including tougher-than-the-president positions in support of job investments, taxes on financial speculators and the defense of Medicare. That’s what DeFazio did in 2010, when he saw off a GOP challenge that suddenly seemed viable as attack ads funded by a Wall Street nemesis of the congressman suddenly filled the airwaves.

Can Democrats in general do better than a presidential nominee who can’t get traction? History says “yes.”

In 1972, when Republican Richard Nixon was crushing Democrati George McGovern by a 60-37 margin nationally, Democrats actually won a majority of the popular vote for House seats and posted a net gain of two Senate seats by defeating entrenched Republican incumbents. One of the Democratic winners that year was a young local official in Delaware, with roots in the civil rights movement and close ties to unions, named Joe Biden.

In 1984, when Republican Ronald Reagan was rolling over Democrat Walter Mondale in the presidential race, Democrats turned out two Republican senators and replaced them with a pair of progressive populists: Paul Simon of Illinois and Tom Harkin of Iowa.

Could something similar happen in 2012? Perhaps. Politics has changed since the ’70s and ’80s. Ideological and partisan divisions run deeper, and freer money has made more incumbents secure. But ticket-splitting still occurs. And a number of Democrats who were supposedly vulnerable made it througfh the party’s 2010 debacle by mounting progressive-populist campaigns that tossed aside party-insider talking points and distinguishing themselves as candidates who did have the word “fight” in their vocabulary.

DeFazio was one of them, as was Iowa’s Bruce Braley, Kentucky’s John Yarmuth and Ohio’s Marcy Kaptur.

DeFazio and his winning compatriots were all founders of the House Populist Caucus, a small group that focuses on jobs, trade and consumer issues in a manner that puts them at odds with Wall Street and corporate-friendly Democrats. There’s a lot of cross-membership between the Populist Caucus and the Congressional Progressive Caucus (Progressive Caucus co-chair Keith Ellison, D-Minnesota, is a Populist Caucus member). What distinguishes the Populist Caucus is its economic focus, which bluntly declares that members are “fighting for working families and the middle class by creating and retaining good-paying jobs in America, providing fair wages, proper benefits, a level playing field at the negotiating table, and ensuring American workers have secure, solvent retirement plans,” seeking “an equitable tax structure,” defending American competiveness by fighting for fair trade principles” and “protecting consumers, so that Americans can have faith in the safety and effectiveness of the products they purchase.”

That’s not an agenda that will make a lot of friends on Wall Street. But it sounds about right for Main Street.

Populist Caucus members are more than happy to share their platform with Obama, whose movement in their direction on a number of issues offers his best prospect for re-election. But Obama is unlikely to go all the way over; for instance, he is extremely unlikely to abandon his support for free trade. That’s a place where Main Street Democrats might distinguish themselves, and win, especially in battleground states such as Iowa, Michigan, Ohio and Pennsylvania.

Most Democrats would prefer that President Obama run for reelection in 2012 as a strong incumbent with strong coattails. But if that is not the case, the extent to which down-ballot Democrats distinguish themselves from the top of the ticket could define the landscape in 2013. It is for this reason that Peter DeFazio’s talk about “distinguishing” Democrats opens an appropriate, if politically challenging, dialogue.