Senate Democrats will have now have one more seat to worry about, with the news that Sen. Herb Kohl of Wisconsin will retire from the Senate.
Kohl, who at 76 has been in the Senate since 1989, was viewed as a relatively safe seat for Democrats since it was thought he could fend off any Republican challenge in part because of his deep pockets as he's done in the past. His money comes from the Kohl's Department Store and grocery change and he owns the NBA's Milwaukee Bucks.
But now the seat is up in the air and will no undoubtedly become a new flashpoint in the ongoing political battles between Republicans and Democrats in the state in which the controversial GOP Gov. Scott Walker has been at the epicenter.
Among the obvious possibilities are Russ Feingold, the former Democratic senator defeated by Republican Sen. Ron Johnson last November. Feingold watchers said after his defeat that they expected that he wouldn't be keeping a low profile for long and would even run for office again.
The Milwaukee Journal Sentinel blog also has some additional names, including Rep. Paul Ryan (R-WI), House Budget Committee chairman whose national profile has risen with his becoming the point person for GOP proposals to cut federal deficits and debt.
Potential Senate candidates on the GOP side include House budget chair Paul Ryan, state Attorney General J.B. Van Hollen and Mark Neumann. On the Democratic side, candidates would include ex-senator Russ Feingold, and U.S. House members Ron Kind of La Crosse and Tammy Baldwin of Madison.
Democrats, desperate to hold onto their narrow Senate majority, have 23 seats to defend while Republicans have 10.
Kohl's departure likely means the Senate Democratic Campaign Committee will need to spend significantly more than it had intended to keep the Wisconsin seat in Senate hands, potentially drawing resources from other races.
The other Democratic senators are Jeff Bingamin of New Mexico, Jim Webb of Virginia, Kent Conrad of North Dakota, Daniel Akaka of Hawaii, and Joe Liebeman, the Connecticut independent who caucuses with Democrats.