President Obama and Democrats have fixated on Mitt Romney's work at Bain Capital as the keynote attack against the Republican hopeful, and recent polls show the attacks are making headway — especially in swing states where Obama has launched attacks over the airwaves.

But while challenges to Romney’s business record appear to be gaining traction, Obama remains vulnerable on an issue that strikes at the heart of the nation's political debate: big government. 

More than one-third of Americans (37 percent) in the latest Washington Post-ABC News poll say Obama’s views on the size and role of government are a major reason to oppose him, while 26 percent say they are a reason to support him. Among independents, Obama's government views are negative by a 2-to-1 margin, 42 to 20 percent (toggle results among all these groups using our interactive poll feature).

By comparison, similar numbers of Americans see Romney’s work buying and restructuring companies as either a reason to support him and a count against (23 and 24 percent, respectively), and 50 percent don’t see it as a major factor at all. 

The story is much different in swing states. In the eight states designated as “toss-ups” by The Washington Post, Bain has a clear negative impact. Thirty-two percent of people in those states say Romney’s work buying and restructuring companies is a major reason to oppose him, while just 16 percent say it’s a reason to support him. This remarkable difference between swing states and the rest of the public mirrors results from a Wall Street Journal/NBC News poll last month, in which those in a broader swath of swing states tilted negative on Romney’s work buying and restructuring companies. Nationally, though, the issue was essentially a wash in that poll, too.

The negative impact of Obama’s views on the size of government is more muted in swing states; 30 percent said they were a major reason to support him in the Post-ABC poll, 34 percent a reason to oppose. 

Nationally, Obama’s challenge is that most Americans see him as a big government guy. Fully seven in 10 Americans believed Obama favors a “larger government with more services” in a Post-ABC poll last September, while just 18 percent said he prefers a “smaller government with fewer services.” That’s upside-down from the overall public, who choose a smaller over bigger government by a 56-to-38 percent margin. 

Unlike Romney’s newly negative image on buying and restructuring companies (at least in swing states), the perception that Obama prefers bigger government is firm. In two other Post-ABC polls in 2010, at least seven in 10 saw Obama favoring big government. And the longstanding nature of this view could make it harder for Obama to shake than the depiction of Romney as a ruthless businessman.