My view of the public is that it doesn’t have strong views on policy matters. But most voters do have strong views about famous politicians. A large minority of voters really like Barack Obama, for example, and if he tells them something is good they’ll assume he’s right. Another large minority of voters has strongly negative feelings toward Obama, and toward the Democratic Party writ large, but has positive views about the Republican Party and its leadership.
Then there’s another, smaller faction that takes a dim view of both parties and of politicians generally. But even though this group is small, it’s centrally located on the opinion spectrum. And it tends to assume that if elite leaders from both parties get together and say something’s a good idea—like George Bush and Dick Cheney but also Hillary Clinton and Tom Daschle and John Kerry and Dick Gephardt say we should invade Iraq—that it’s probably a good idea. On the contrary, if only one party will support something then it’s probably partisan and bad and probably the party pushing the idea didn’t try hard enough to reach a sensible compromise.
Therefore, almost anything that an opposition party succeeds in mounting unanimous opposition to—Bill Clinton’s 1993 budget, George W Bush’s 2005 Social Security privatization push, Barack Obama’s 2009 health reform push—will wind up polling poorly.