The move comes in the wake of a contentious battle this week in the Senate over the confirmation of Neil Gorsuch
when the Republicans who control the chamber used the "nuclear option"
to neutralize the filibuster for nominees to the Supreme Court.
"We are writing to urge you to support our efforts to preserve existing rules, practices, and traditions as they pertain to the right of Members to engage in extended debate on legislation before the United States Senate," said the letter that was spearheaded by GOP Sen. Susan Collins of Maine and Democratic Sen. Chris Coons of Delaware. "Senators have expressed a variety of opinions about the appropriateness of limiting debate when we are considering judicial and executive branch nominations. Regardless of our past disagreements on that issue, we are united in our determination to preserve the ability of Members to engage in extended debate when bills are on the Senate floor."
In the days leading up to Gorsuch's confirmation, Collins and Coons led bipartisan negotiations to try to head off the nuclear option, which changed the Senate rules over the objection of Democrats in the same way that in 2013 Democrats used the nuclear option to make it easier to confirm President Barack Obama's executive branch and lower-court nominees.
Collins said the issue of filibustering nominees had become so politically fraught that there was little trust between the two sides, causing the talks to collapse earlier this week. She and Coons then spent the last day and a half gathering signatures for their letter.
Recovering from an ankle injury, Collins was seen hobbling around the Senate floor during votes, holding a green folder containing the letter, and talking individually to senators about it.
Many senators are concerned that getting rid of the 60-vote filibuster for legislation would make it so whichever party is in the majority could ram bills through and diminish the Senate's traditional role of slowing down legislation and finding bipartisan solutions.
The signatures of 28 Republicans, 32 Democrats and one independent is evidence that a broad mix of senators will back the filibuster for legislation.
"We are mindful of the unique role the Senate plays in the legislative process, and we are steadfastly committed to ensuring that this great American institution continues to serve as the world's greatest deliberative body," said the letter that was sent to Majority Leader Mitch McConnell, R-Kentucky and Senate Minority Leader Chuck Schumer, D-New York. "Therefore, we are asking you to join us in opposing any effort to curtail the existing rights and prerogatives of Senators to engage in full, robust, and extended debate as we consider legislation before this body in the future."
Both McConnell and Schumer support maintaining the 60-vote threshold.