MADISON, Wis. -

State Sen. Luther Olsen has easily beaten back a challenge from a tea party supporter in a Republican primary.

Unofficial results from Tuesday's election show Olsen with 78 percent of the vote and David Wayne Eiler of Brandon with 22 percent with 96 of 148 precincts reporting.

Olsen, of Ripon, has held his seat in the 14th Senate District in south-central Wisconsin since 2005. He survived a recall election a year ago spurred by his support for Republican Gov. Scott Walker's plan to strip most public workers of their nearly all their union rights.

Olsen was the only state senator to face a primary challenge Tuesday. He advances to face Democrat Margarete Worthington in November's general election.