WASHINGTON (AP) -- Two veteran Republicans, former Wisconsin Gov. Tommy Thompson and Florida Rep. John Mica, are facing strong challenges from insurgent conservatives in primary contests that reflect the rift in the GOP between grass-roots conservatives and the party's establishment candidates.
Those races headline Tuesday's primaries in four states, including Connecticut and Minnesota.
Wisconsin and Florida are the latest battlegrounds for tea party forces and other conservative activists hoping to add to big wins this year in the Indiana and Texas GOP Senate primaries.
Tea party candidates scored major gains in 2010 congressional races, but they've had mixed success since.
Thompson served as Health and Human Services secretary under President George W. Bush.
He's in a tough four-way U.S. Senate race, with his challengers casting themselves as closer to today's more conservative GOP.