Rep. Mike Simpson (R-Idaho) easily defeated Bryan Smith in an expensive House primary Tuesday that pitted the business wing of the GOP against the tea party insurgency.

The campaign was the latest staging ground for a fight that is playing out across the country this year. Business groups are redoubling their efforts to protect more moderate Republicans against tea party challengers in races such as the one in Idaho’s 2nd District.

“I think the business community is being much more diligent and thorough in the process of investing time and resources in primaries,” said David French, the chief lobbyist at the National Retail Federation, whose political action committee supported Simpson.

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