I’m skeptical about Republican Tim Michels beating Democratic senator Russ Feingold in the Wisconsin Senate race, but a friend at the NRSC just sent me tracking numbers that show Feingold’s lead slipping from 13 points to 5 points in four days:

10/26 — Feingold 52 percent, Michels 39 percent

10/27 — 51-41

10/28 — 49-41

10/29 — 48-43

Some Republicans have said all along that Wisconsin is their dark-horse race.