Senior Leader Carl Levin announces retirement opening Michigan Senator battle to be tight contest

Senate stalwart Carl Levin will not seek re-election

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Senator Carl Levin (R) and Senator John McCain hold a news conference about filibuster reform on Capitol Hill December 28, 2012 in Washington, DC. Levin, a six-term Democrat and fierce advocate for military personnel and readiness, announced Thursday he will not seek another term. | Democracy, elections and voting at Democracy Chronicles