Newt Gingrich stumps with Tommy Thompson in Wisconsin

Newt Gingrich stumped with former Wisconsin Gov. Tommy Thompson (R) on Tuesday, just one week ahead of a hard-fought Senate primary between Thompson, businessman Eric Hovde (R) and former Rep. Mark Neumann (R-Wis.).

"I believe we need a senator who actually knows what they're doing," Gingrich said, according to the LaCrosse Tribune, in an apparent shot against first-time candidate Hovde and Neumann, who Gingrich sparred with while both were in Congress in the 1990s. "We need people who have the knowledge and experience and the skills of getting things done ... I believe he can reach across the aisle and actually help make the Senate effective in a way nobody else in this race could."

Gingrich is the latest Republican to throw his support behind Thompson, who also has the backing of former Arkansas Gov. Mike Huckabee (R) and Indiana Gov. Mitch Daniels (R) as well as rocker Ted Nugent.

Recent polls show a tight three-way race between the candidates, with Wisconsin state Assembly leader Jeff Fitzgerald (R) in a distant fourth place. The primary has taken on increasingly nasty tones, with all candidates crying foul about each other's attacks and leveling harsh charges against one another.

The winner of the Aug. 14 primary will go on to face Rep. Tammy Baldwin (D-Wis.) in what could be a tight general election race.

The Democratic Senatorial Campaign Committee used Gingrich's endorsement to take a shot at Thompson's work for Beltway firms after he left former President George W. Bush's Cabinet.

"Newt Gingrich and Tommy Thompson lobby on behalf of special interest clients but avoid ethics laws that would require them to register as lobbyists. This baggage cost Newt the election and it is certain to cost Thompson the election as well," said DSCC spokesman Matt Canter. "Thompson's experience peddling influence might make him a great lobbyist for special interests but he'd make a terrible senator for Wisconsin families."

This post was updated at 1:55 p.m.