The Las Vegas Sun and The Associated Press are reporting they've been told by sources with first-hand knowledge that Sen. John Ensign (R-NV) will announce this afternoon that he won't seek re-election in 2012.
As the Sun reminds us:
"Ensign, whose name was once being tossed about for a presidential run, ran aground politically in 2009 when he announced he had an affair with Cynthia Hampton, a campaign aide whose husband, Doug Hampton, had been Ensign['s] deputy chief of staff.
"Ensign's parents paid the Hamptons and their two children $96,000, and Ensign allegedly assisted Doug Hampton in finding alternate employment — moves that may have broken Senate rules."
If you're keeping tab on such things, as Frank does over at It's All Politics, four Democratic senators and, now, three Republicans and an independent (Joe Lieberman of Connecticut) have said they won't be running next year.