As for Johnson, the big question is will he or won't he (seek reelection, that is). In 2006, Johnson suffered a very scary and dangerous stroke-like episode involving bleeding in the brain which required emergency surgery and extensive rehabilitation. The incident still affects his mobility and speech, but reports over the years indicate he has improved markedly, and his mental acuity never suffered, though he sometimes still uses a wheelchair.
Johnson did avoid a serious challenge in 2008, since his long recovery made top-tier Republicans wary of jumping in and running an aggressive race lest they look callous. But he had a couple of pretty remarkable wins under his belt prior to that. His first victory in 1996 came against GOP Sen. Larry Pressler, and let's just say that unseating a Republican incumbent (who isn't under indictment) in a red state in a presidential year is truly a hell of a thing. In 2002, Johnson was a top GOP target but managed to win narrowly against John Thune—the same John Thune who went on to beat Senate Minority Leader Tom Daschle just two years later.
So his physical condition may not be tops, but Johnson is quite the politician. And he's sounding more enthused about the possibility of another run than, say, Jay Rockefeller is in West Virginia:
"As in past campaigns, I will make my formal announcement later next year," he said in the statement. "But I feel great, still have work to do, and I fully intend to put together a winning campaign in the weeks and months ahead."I wouldn't take that one to the bank just yet—after all, he could dispel any retirement talk with the snap of his fingers if he chose to— but I'm pleasantly surprised to hear Johnson sounding so game. While Democrats do have some possible replacement options (such as ex-Rep. Stephanie Herseth Sandlin) if Johnson does call it quits, I'm quite convinced he's our best hope of holding this seat and I certainly hope he runs again.