What is it?:Obamacans are the new army of American voters rising up in support of Democratic presidential hopeful Barack Obama. They are riding on a tide of enthusiasm for Obama.

Who are these Obamacans?

Obamacans are Republicans who have switched allegiance to the Democratic party or, more specifically, to Barack Obama. Obamacans have traditionally voted for Republican candidates, but such is the charisma of the man that they are crossing party lines.

Why on earth would Republicans switch over?

Call it the Kennedy effect, or call it Obamania, but Obama's mantra of change seems to have captured the imagination of voters on both sides of the electoral divide. Many Republicans who feel that their presidential candidate, John McCain, is just coming out with the same old baloney are attracted by Obama's vision and mesmerised by his superb speaking skills. Although he comes on like a Kennedy, and is a liberal, many Republicans see him as a younger version of Ronald Reagan.

What evidence do we have of these Obamacans?

A recent poll of registered voters found that 14 per cent of Republicans would happily vote for Barack Obama in the upcoming election. Some high-profile Republicans have "whispered" their support, and Obama, in what has been called a "brilliant strategy", has seized on these soft-spoken messages of approval and turned them to his advantage.

Sounds like McCain's got a fight on his hands.

Don't write him off just yet. The same poll found that 17 per cent of Democrats would also cross party lines and vote for McCain. These are Democrats who believe that the US should remain tough on terror, and are reassured by McCain's hawkish message.

Don't tell me, they're called McCainocrats?

Good guess. If Obama wins the Democratic presidential nomination, the battle between the Obamacans and the McCainocrats is sure to hot up. But there is another, covert army of Obamacans who are voting Democrat for more sinister reasons. These are the Republican voters in open-primary states who vote Obama simply because they can't abide the idea of Hillary Clinton becoming president. So, on primary day, they vote for Obama, ensuring that he wins that state, and then, having influenced the Democratic nomination, they switch back to their own party and vote McCain in November.

Try at work:

"So let me get this straight, you used to be a McCainocrat, but then changed your mind and became an Obamacan. Er, what party are you with?"

Try at home:

"I'm voting for Obama, but I told the guys at work I'm voting McCain. I'm living a double life."