This one i think is a bit unqiue.....from reading the articles he's simply tired of the far extremes of each party running the show and not working together.From polling ,his seat did not seem to be in too much danger come the mid terms.Sad to see guys like this give up in frustration.Centrists in both parties are being squuezed out.It's not a good sign for the Republic.
http://www.cnn.com/2010/POLITICS/02/15/bayh.retirement/index.html?hpt=T1
http://www.cnn.com/2010/POLITICS/02/15/bayh.retirement/index.html?hpt=T1