To this list I would add Richard Shelby of Alabama.
http://www.aei.org/publications/pubID.22451,filter.all/pub_detail.aspThese Five Senators Know Better Than to Go Nuclear. Don't They? By Norman J. Ornstein
Roll Call
Publication Date: May 4, 2005
The fate of the Senate now rests in the hands of a handful of Republicans who have been great figures of the Senate, custodians of its traditions and its essence. They will soon come to a crossroads on the “nuclear” option and the filibuster.
A few are uncommitted on the question; others are presumed to be aligned with Senate Majority Leader Bill Frist (R-Tenn.). All, I believe, know better, and each will be judged by history on their choice in this matter. They include Dick Lugar of Indiana, Ted Stevens of Alaska, John Warner of Virginia, Thad Cochran of Mississippi and Pete Domenici of New Mexico.
In 1976 and 1977, I served on the staff of a Senate select committee charged with reorganizing the Senate’s committee system. Following the customary practice, the 12 Senators on the panel were evenly divided between the two parties. The assignment was the fifth or sixth committee for each of the members, ensuring that few of the 12 spent any time at all on the panel’s work. But one who did was Domenici, then a freshman.
One late evening as we worked, I turned to Domenici and asked him why he was spending so many hours on a thankless task like ours. After all, his constituents would never notice, and any changes we recommended for committee numbers and jurisdictions were likely to be opposed vigorously by the committee chairmen and other power-brokers. He replied that service in the Senate was the highest honor he could receive, and he was determined to leave the place a better institution than when he arrived.