In New Mexico, where Republican governor Susana Martinez won her first term in November, incumbent Democratic senator Jeff Bingaman will announce today he won't seek another term in 2012. Chris Cillizza writes:

Bingaman is the fourth Democratic (or Democratic-aligned) Senator to announce that he will not run for re-election in 2012, joining Sens. Jim Webb (Va.), Joe Lieberman (I-Conn.) and Kent Conrad (N.D.) on the sidelines.

Two Republicans -- Sens. Jon Kyl (Ariz.) and Kay Bailey Hutchison(Texas) -- are not running for new terms.

Democratic strategists, while disappointed in Bingaman's decision, cast the decision as part of a broader strategy put in place by Democratic Senatorial Campaign Committee Chairwoman Patty Murray (Wash.) to force members on the fence to make their intentions clear early on.

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