Chafee to vote no on Judge Alito

Sen. Lincoln Chafee (Rino-RI) has announced his intention to vote against Judge Alito's confirmation as a Supreme Court justice. Chafee is the first "Republican" to come out against Judge Alito. Can anyone explain why the Republican National Committee is supporting Chafee against Mayor Steve Laffey in the upcoming primary? Anchor Rising has Laffey's response to Chafee's decision.

UPDATE:
Here is a link to ElectLaffey, the official website for Steve Laffey's campaign.