Sen. John Kyle (R-AZ) is planning to announce his retirement today, according to Chris Cilliza of the Washington Post:Arizona Sen. Jon Kyl (R) plans to announce his retirement at a press conference later today, according to a high level source familiar with his thinking.Kyl will be the fifth Senator to announce he is leaving the chamber in 2012. He joins Sens. Joe Lieberman (I-Conn.), Kent Conrad (D-N.D),Jim Webb (D-Va.) and Kay Bailey Hutchison (R-Texas) on the sidelines.Kyl is the Senate Majority Whip, the second ranking position in Republican leadership.Kyl was term-limited out of that job in December 2013 and would have been forced into either challenging Sen. Mitch McConnell (R-Ky.) for leader or leaving leadership all together.Kyl's retirement make this race much more competitive, but the GOP would still be favored.  The GOP had a good year in Arizona in 2010,  picking up two House seats, and almost winning two...(Read Full Post)