Former Gov. Tommy Thompson revealed plans to supporters over the weekend to run for the U.S. Senate in the upcoming election to fill the seat of Democratic Sen. Herb Kohl.

Thompson plans to formally kick off his campaign Dec. 1 with an event in the Weldall Manufacturing building in Waukesha, Wis.

In an email sent Saturday inviting supporters to the event, Thompson said the outcome of the race for Wisconsin’s open Senate seat could have a great effect on the national government’s political future, particularly in regard to the United States’ mounting debt.

“This election may determine whether the Democrats are successful in running up America’s debt,” Thompson said in the email. “The challenges Washington faces are tremendous, but I’ve tackled big problems before using Wisconsin common sense.”

In the email, Thompson said Congress’ priorities should be balancing the budget, reforming entitlements, reforming the health care system and repealing “Obamacare,” and allowing the economy to grow with low taxes, fewer regulations and free enterprise.

Thompson will be running against former U.S. Rep. Mark Neumann and current state Assembly Speaker Jeff Fitzgerald, R-Horicon, in the Republican primary. As of now, the winner would be running against current U.S. Rep. Tammy Baldwin, the only Democrat to announce candidacy in the race so far.

Executive Director of Common Cause in Wisconsin Jay Heck said Thompson is the clear frontrunner for the Republicans but may face challenges against his opponents who have been more visible in recent news.

“Thompson will raise money, there’s no question there, but he hasn’t been on the ballot since 1998,” Heck said. “He may not be as conservative as [Neumann or Fitzgerald], and in a Republican primary more conservative is helpful.”

According to figures from Real Clear Politics, Baldwin is slightly behind Thompson in the pre-primary polls.

Heck said Baldwin’s biggest issue will be visibility.

“She will get money from the national lesbian and gay community as well as other labor advocate groups, and she is a powerful fundraiser,” Heck said. “But where she will need to work is becoming visible in the public eye.”

Baldwin’s campaign office was not available to speak about her plans to gain visibility for her campaign across the state.