Sen. Ron Johnson and former Sen. Russ Feingold are preparing for their second and final debate with just two weeks left in one of the nation's most closely watched Senate races.

Tuesday's debate at Marquette University Law School comes just four days after the two men tussled over Donald Trump, veterans' issues and a range of other policy questions.

The rematch between Johnson, the Republican who quit the business world in 2010 to unseat the Democrat Feingold, is seen as one of the chamber's likeliest seats for a possible flip.

The 90-minute debate will take place on the same day a new statewide poll from St. Norbert College showed Feingold leading the race 52 percent to Johnson's 40 percent, with a margin of plus or minus almost 3.8 points.  A Marquette law school poll a week ago had the race even.