Former Wisconsin Gov. Tommy Thompson (R) is "50-50" on whether or not to challenge Sen. Russ Feingold (D) "and will almost certainly make a decision before the May 20 state party convention," the Washington Post reports.
Said a source: "He has been in public service his entire life. This is not something you take lightly."
"It's not clear whether Thompson's current indecision is evidence of progress toward a candidacy or movement away from a run."