Until recently, Americans would be most likely to compare China's spiky-haired piano virtuoso Lang Lang to the late, great showman Liberace. But yesterday, conservative commentators were likening "the pianist more famous than the Beatles", to a Nazi court musician.

The reason – "My Motherland", the popular patriotic song he played at the White House reception for President Hu Jintao, was the theme tune to a 54-year-old, long-forgotten Korean War movie, The Battle of Shangganling Mountain. According to U.S. conservatives, Lang Lang chose an anti-American song, or had it chosen for him, as a deliberate snub to his hosts.

After two years of Tea Partying, we should be used to the craziness of American right wing politics. But by fingering Lang Lang as a closet nationalist, or worse, a secret agent of the Chinese government, right wing commentators have reached new levels of absurdity.

Writing in the National Review, Jay Nordlinger likened Lang Lang to an official artist to the Nazis, and recalled an earlier offense.

"He played at the White House event for Paul McCartney — the one at which McCartney made a ridiculous anti-Bush crack, which caused Lang Lang and the Obama crowd to laugh like hyenas."

Note the contemptuous reference to Obama. U.S. right wingers tend to hate America's President much more than they hate any of its supposed foreign enemies.

U.S. spokesman Tommy Vietor insisted "any suggestion that [Lang Lang's performance] was an insult to the United States is just flat wrong." But White House denials made no difference, as a growing cast of characters, including Fox News host Glenn Beck, announced themselves willing to be insulted on its behalf.

Admittedly, the fuss wasn't confined to Washington. In China, some of the "whatever" faction of liberals (as in whatever the U.S. does is right) insisted Chinese officials must have approved the "insult". And permanently enraged young nationalists hailed the flamboyant and rather camp Lang Lang for apparently giving the finger to the Americans on their home turf.

But the spat mainly reflects the increasingly unhinged nature of American political discourse. It is a paradox that as policy differences between Democrats and Republicans have narrowed, on most issues, to a wafer thin gap, partisan rhetoric has plumbed new depths.

Before the recent shooting of Democratic Congresswoman Gabrielle Giffords, her image had appeared in the crosshairs of a gun sight on Sarah Palin's website. An extreme right wing Christian organization - the Westboro Baptists - announced it was to picket the funeral of a nine-year old girl who was killed in the shooting. Conservatives are now campaigning for Gifford's local sheriff to be sacked because he called for a cooling of political rhetoric in the wake of the shooting.

With 14 million unemployed, a flatlining economy, and no strategy for recovery beyond reflating asset bubbles - not to mention a perception that world dominance is slipping out of their grasp - it is perhaps no wonder some Americans are attracted by extreme right wing rhetoric. It is in this context we should understand the irrational accusations against the harmless young musician Lang Lang.