Posted Tuesday, November 6, 2012 --- 7:00 a.m.

MADISON, Wis. (AP) -- Democrats are looking to Rep. Tammy Baldwin to hold off a political comeback by former Gov. Tommy Thompson and prevent Wisconsin's open U.S. Senate seat from falling into Republican hands.

The GOP sees the seat as a key pickup opportunity Tuesday even though it's has been held by a Democrat since 1957.

Thompson served 14 years as governor before leaving in 2001 to join President George W. Bush's administration. He's never lost a statewide election, but he's on the ballot for the first time since 1998.

Baldwin is a seven-term congresswoman from Madison. If she wins, she'd become the first openly gay candidate elected to the Senate.

The race is attracting national attention as Republicans try to win a Senate majority. Overall spending on the race has topped $65 million.

Copyright 2012. The Associated Press.