WAUSAU, Wis. (WHBL) - The two main candidates in an extremely tight U-S Senate race in Wisconsin will debate each other tonight. Republican Tommy Thompson regained his earlier lead over Democrat Tammy Baldwin by just one percentage point, 46-45, in the latest Marquette Law School poll released yesterday. The race is considered a dead heat, because the results are well within the poll’s three-point-four-percent margin-of-error. Tonight’s debate begins at seven o’clock from the U-W Marathon County campus in Wausau. It will be broadcast live on Wisconsin Public Television and Channel 4 in Milwaukee, and will be streamed live at several places on the Internet including the Journal Sentinel Web site and Wisconsin Vote-Dot-Org. Andy Moore of Wisconsin Public Television says the format will require Thompson and Baldwin to dig deeper into issues, beyond their normal campaign speeches. Yesterday, New Jersey Governor Chris Christie campaigned for Thompson in Green Bay. And last night in Waukesha, 2008 G-O-P White House candidate John McCain and his fellow U-S Senator Lindsey Graham were at reception for Thompson. Baldwin plans to appear with former President Bill Clinton tomorrow night in Green Bay. She’ll also be with First Lady Michelle Obama as she campaigns in Racine and Wausau during the day tomorrow. Baldwin has the financial edge, with three-and-a-half million dollars in her campaign fund at the start of October compared to two-million for Thompson. Outside groups are spending millions more on both sides. Karl Rove’s G-O-P group has spent five-million dollars on the Wisconsin Senate race in the last two months – and it unveiled a third major ad campaign yesterday.