Montana's junior senator, Democrat Jon Tester, made a proposal Wednesday to his challenger in the 2012 election, Republican Rep. Denny Rehberg: "I am asking Congressman Rehberg to join me in taking an unprecedented stand. I am asking him to join me in rejecting all third-party radio and TV ads during the remainder of this campaign. "

Tester made the proposal during a telephone press conference.

Tester sent a letter to Rehberg and a copy of an agreement, already signed by the senator, pledging to not allow, and to try to stop, third-party advertisements in Montana through Election Day.

"T...