Because if you say it enough it becomes a plausible theory. See: Creationism. See also: "Bush caused the recession of 2000-2001"
complaints, "OJ was framed", etc...
Hell, Bush had half the country thinking the inheritance tax will wipe out their families. And amaziongly, he's got the very people getting bent over Ned Beatty-in-Deliverance style by the current economy eating some hogwash about how he's "creating jobs."
The funniest people are the guys losing jobs but nevertheless voting for Bush because "He has values." Yeh, he does... but do you buy stock in a corp because the CEO is a God-fearing churchgoer? Well, how is the President any different than a CEO? If your sense of being is that entwined with the message of a politician, you've got to stop dwelling on "values' and seek a shrink about "issues." I don't give a fuck if my president is giving dirty Sanchezes to half the interns and wiping his fingers in the Declaration of Independence afterward so long as he's wisely stewarding the economy...