MADISON, Wis. (AP) -- Democrat Tammy Baldwin and Republican Tommy Thompson are meeting for their third and final debate before the election for the Wisconsin's open U.S. Senate seat.
The debate Friday night is in Milwaukee on the Marquette University campus.
Polls show the race to be virtually tied, with more than $40 million being spent by both the candidates and outside groups.
It is one of the most expensive races in the country. With Republicans needing at least three seats to take over majority control, or four if Mitt Romney is elected president, whoever wins Wisconsin could determine which party takes control.
Baldwin and Thompson have been sparring in recent days over actions they took in the years following the 9/11 terrorist attacks, their positions on health care reform and Iran.