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US Tea Party movement gathers momentum

15 September 2010 Last updated at 22:54 BST

There is more evidence of the Sarah Palin effect in the US as yet another of her supporters won the right to represent the Republicans in the mid-term elections.

It is the latest victory for the anti-establishment Tea Party Movement championed by Ms Palin.

But victory for the movement may damage the Republicans' electoral prospects - as Mark Mardell explains.