Today's fun news is that over half of all Republicans are willing to tell a pollster (well, a robopolling call) that they believe that ACORN stole the 2008 election for Barack Obama. John Sides has several good points about the poll, and about not reading too much into it.
I can add two things. First, the analogy John makes (as does Eric Kleefeld at TPM) to the 2000 election isn't the right one to work from. While Democrats could spin conspiracy theories about 2000, they didn't have to; in that contested election there were plenty of real evidence that people could turn to if they thought the wrong candidate had been installed in office. The correct comparison is to 2004, and the conspiracy theories most notoriously advanced in this article that Diebold stole the election for George W. Bush in Ohio. I don't know if there's polling on 2004, but I think that's a lot more relevant comparison than 2000.
The second is just to highlight that when conservatives attack ACORN, they believe (or at least conservative rank-and-file voters believe) that they're actually attacking a very, very, important organization. Again, I think this is almost totally identical in content to liberal attacks on Diebold during the Bush years. Democrats who want to understand anti-ACORN rhetoric should see it as similar to the Diebold story, as opposed to seeing it as similar to attacks on, say, Planned Parenthood.