Another day, another senator announces retirement. Sen. Jon Kyl (R-AZ) will announce Thursday his intention not to run in 2012. Kyl’s term as Senate Majority Whip, the second-highest ranking Republican position, was to expire in 2013. He would have had to either face off against Sen. Mitch McConnell (R-KY) for leader or become an ordinary senator. Instead, he’s decided to join the ranks of Joe Lieberman (I-CT), Kent Conrad (D-ND), Kay Bailey Hutchison (R-TX), and Jim Webb (D-VA) and leave the Senate altogether. Republican contenders for his seat include former Rep. John Shadegg and Rep. Jeff Flake. Democrats likely to take a run include former state party chairman Jim Pederson and former state Attorney General Terry Goddard.