Chris Murphy to join Bysiewicz in race for Lieberman's seat

Rep. Chris Murphy announced his candidacy for Senate today, becoming the second Democrat to run for retiring Sen. Joe Lieberman's Connecticut seat and setting up the first of what are expected to be many high-profile Senate primaries in 2012.

"I've decided to run for the United States Senate in 2012 because I believe that I can be a stronger voice for the issues that matter to Connecticut, like creating good jobs and ending these costly wars, in the Senate," Murphy said in a statement released this morning.

Murphy is set to make a more public announcement early this evening at the Waverly Inn in Cheshire, Conn., according to a source who asked to be anonymous because the decision is not yet public.

Murphy joins former Secretary of State Susan Bysiewicz, who launched her campaign Tuesday, in the Democratic primary. Lieberman announced Wednesday that he would not seek reelection.

The matchup between Murphy and Bysiewicz will be one of the biggest primaries in the country, with both candidates claiming strong political operations and plenty of name ID to start with. Both campaigns have internal polls showing their candidate with a lead. There's also the possibility that the race could grow to include a really big name -- Ted Kennedy Jr. -- and/or another congressman -- Rep. Joe Courtney (D-Conn.) -- which would make it one of the biggest Senate primaries in recent history.

But it will by no means be the only high-profile primary.

Already, Republicans appear headed for a busy season. Competitive primaries are forming for open seats in North Dakota and Texas, as well as the primaries to face Sens. Jim Webb (D-Va.), Claire McCaskill (D-Mo.), Bill Nelson (D-Fla.) and Ben Nelson (D-Neb.). And that's not to mention the Republican incumbents who could face viable primary challenges, including Sens. Orrin Hatch (R-Utah), Richard Lugar (R-Ind.), John Ensign (R-Nev.) and Olympia Snowe (R-Maine).

Democrats appear headed for primaries to face Sen. Scott Brown (D-Mass.) and potentially for seats in North Dakota and Texas left open respectively by the announced retirements of Sens. Kent Conrad (D) and Kay Bailey Hutchison (R).

The GOP could also have a primary in Connecticut, where two 2010 Senate candidates -- former Rep. Rob Simmons and former wrestling executive Linda McMahon -- are looking at running.

Get ready for another fun Senate primary season. The Republican presidential race won't be the only game in town.