( UPDATE: Video added below.)

The nightmare comes in different versions. You show up for the first day of class, but it's really the final exam. You're introduced to speak to a large audience and totally forget what you're supposed to say.

For a politician, especially one running as a uniter for president of these 57 United States, it's something else. And just now it happened up in South Dakota which is right next to Iowa, which means they are different states.

The Democratic frontrunner Sen. Barack Obama of another state, Illinois, had an enthusiastic double-barreled stump introduction from two local luminaries, former Sens. Tom Daschle and George McGovern, who was an equally enthusiastic supporter of Sen. Hillary Clinton until recently. But he changed his mind.

McGovern knows a little about presidential races, having once been the Democratic presidential candidate himself way back in 1972. He lost though.

Both South Dakotans lavished all sorts of praise on Obama, according to reporters present, including The Times Nicholas Riccardi. As the large, enthusiastic crowd of some 7,000 supporters roared and waved "We can do it" signs and Bruce Springsteen's "The Rising" blared, Obama bounded onto stage, grabbed the microphone and said, "Thank you, Sioux City!"

Trouble is, Obama was in Sioux Falls.

So was the crowd, which suddenly fell silent. Where are those Southwest Airlines get-away flights when you need them?

"I'm sorry," Obama quickly caught himself. "Sioux Falls. I've been in Iowa too long." Now, that line may not go over too well in the Hawkeye State, which gave him his first big caucus win way back in January.

Obama went on to give yet another rousing stump speech, seeking support in the state's primary June 3, the last one along with Montana. The Dakota crowd was enthusiastic. And the freshman Illinois senator threw in several extra references to South Dakota for good measure.

On to who knows where now? More below.

And a hat tip to Cassy Fiano.

(UPDATE: In its story today on Obama's appearance and his geographic gaffe, the local newspaper's website, the ArgusLeader.com, made its own gaffe with the initial headline: "Obama starts speech with a gaff" )

— Andrew Malcolm