There is nothing self-hating liberals love more than to be told they're elitists who detest and fear the real America. So when Gerard Alexander pitched an essay to the Washington Post explaining why liberals are so condescending, the editors must have been overcome by paroxysms of joy.

"See how we grovel!" you can imagine them thinking. "Surely no one will accuse us of liberal bias if we are willing to publish a conservative screed as mendacious as this."

Alexander's piece, published on Sunday, is filled with dubious assertions and strawman arguments from beginning to end. But it was not until I was almost through it that I came across a passage so ridiculous that I burst out laughing. Alexander writes:

"Some observers have decried an anti-intellectual strain in contemporary conservatism, detected in George W Bush's aw-shucks style, Sarah Palin's college-hopping and the occasional conservative campaigns against egghead intellectuals."

Whatever case liberals wish to make against Bush, I am reasonably confident that it has nothing to do with his hail-fellow-well-met persona. His unthinking blunders into war, torture and trillion-dollar-plus deficits have rather more to do with it.

But it was the idea that liberals hold Palin in contempt because she switched colleges a few times that had me in hysterics. The real problem is that none of those colleges taught her not to answer "we win, they lose" when asked about her approach to foreign policy.

Then again, this is a woman who prayed for God to build a natural-gas pipeline, and who delivered a cheery greeting to a rightwing hate group that wanted Alaska to secede from the United States. (The first dude, Todd Palin, was actually a member.) Trust me on this, Dr Alexander: Palin's propensity for switching colleges is the least of it.

Alexander, a political-science professor at the University of Virginia, criticises Barack Obama for complaining that he's been characterised as a "Bolshevik", ignoring the fact that his opponents regularly refer to him as a "socialist". He rips New York Times columnist Paul Krugman, a Nobel Prize-winning economist, for a blog post in which Krugman went after the Wall Street Journal's editorial page. And he somehow finds fault with author Thomas Frank and 2004 Democratic presidential candidate Howard Dean for observing – correctly – that Republicans succeed in large measure because they use rightwing positions on social issues to induce working people into voting against their economic self-interests.

Weirdly enough, Alexander even cites a poll of Republicans commissioned by the liberal blog Daily Kos as evidence that liberals look down on conservatives. You would think the poll results themselves might give Alexander reason to pause: 39% believe Obama should be impeached; 63% say he's a socialist; 58% think Obama was either born outside the United States or aren't sure; and 31% believe Obama is "a racist who hates white people".

Alexander doesn't bother to dispute the methodology of the poll. Instead, he blandly asserts, "I doubt it would take long to design a survey questionnaire that revealed strange, ill-informed and paranoid beliefs among average Democrats."

What does Alexander mean? He provided an answer in an online chat with readers on Monday. In response to a sensible comment noting that conservatives are far more likely than liberals to believe that evolution is false, global warming is a hoax and Obama was born outside the US, Alexander responded:

"[W]hich group is more likely to believe that the Bush White House had advanced warning of al-Qaida's attack on the US? That Aids was developed in a US military lab and used deliberately to infect people? That oil companies take as profit most of what we pay at the pump?"

In other words, crazy opinions based on falsehoods that have become mainstream thought among Republicans are no worse than crazy opinions based on falsehoods that are held by a tiny fringe group on the far left. Oh, blessed balance. (And why did he throw in that bit about the oil companies? I think we all know that "most" of what we pay for gasoline isn't profit, but does anyone question that the oil business isn't pretty damned lucrative?)

The new poster boy of the Republican party, Massachusetts senator Scott Brown, got elected in part by claiming that last year's $787bn stimulus package "failed to create one new job". It's a statement that brands him as being fundamentally unserious. Last fall, Mark Zandi, chief economist for Moody's Economy.com and an adviser to John McCain during the 2008 presidential campaign, told the New York Times that the stimulus had created or saved more than 1.1 million jobs, and that, if anything, it should have been bigger.

It's hard not to be condescending in light of Brown's ignorant (or cynical) remarks, or Oklahoma senator James Inhofe's religious crusade against atmospheric science, or the never-ending debate over so-called intelligent design, which is nothing more than creationism dressed up in academic garb.

"American liberals, to a degree far surpassing conservatives," Alexander writes, "appear committed to the proposition that their views are correct, self-evident, and based on fact and reason, while conservative positions are not just wrong but illegitimate, ideological and unworthy of serious consideration."

There's a reason for that, but it's not the one Alexander wants you to believe.