Image caption The clown has not been publicly identified - but his actions have been roundly denounced by politicians of all stripes

The Missouri State Fair has banned for life a rodeo clown who donned a mask bearing the likeness of President Barack Obama for a mocking comedy act.

The clown's act on Saturday night - during which fans were asked whether they wanted to see "Obama run down by a bull" - drew swift denunciation.

Fair organisers said on Monday the act was "inappropriate" and apologised for the "unconscionable stunt".

A spokesman for Gov Jay Nixon said the clown's act was "deplorable".

Rodeo clowns are an established part of the sport in the US.

In addition to entertaining the fans with comedy sketches between bull riding and other competitive feats, they distract the bulls once they have thrown their riders, in order to give the cowboys a chance to escape.

The most popular rodeo clowns can take in $2,000 (£1,293) per night at the largest events, according to the US Bureau of Labor Statistics.

In amateur video taken of the event in Sedalia, Missouri, a performer wearing what appears to be a toothy Obama fright mask, jacket, and straw cowboy hat can be seen standing in the middle of the rodeo arena.

The announcer is heard calling attention to him, at which point a voice cries over the public address system: "I know I'm a clown, he's just running around acting like one, doesn't know he is one."

The unidentified clown's numerous detractors have insisted rodeo is a competitive sport and a brand of family entertainment, not a political platform.

"All members of the Missouri Rodeo Cowboy Association are very proud of our country and our president," the association's board of directors said in a statement.

"This type of behaviour will not be tolerated."

State Representative Steve Webb, like Mr Obama a Democrat, suggested the act had "racial overtones", in an interview with the Kansas City Star.

In 2012, Mr Obama lost the state of Missouri in the US Midwest 54% to 44%. But in 2008, he lost the state by fewer than 4,000 votes (0.12%).