The four-term, 76-year-old senator is the sixth Democrat or Joe Lieberman to forgo reelection in 2012, and with each retirement the GOP’s chances of taking control of the Senate continue to grow. Former Democratic senator Russ Feingold, who was kicked out of office last November, is assumed to be interested in the seat, and Republican congressman Paul Ryan will get a lot of buzz as well. If they both run, it will be one of the country’s marquee match-ups. [Fix/WP]
