Veteran Senate Democrats agree the chamber’s rules need to be changed to break the current legislative logjam, but some fear detonating a procedural “nuclear” device that could throw the chamber into further gridlock.

There’s a general consensus on the Democratic side that Majority Leader Harry Reid should act to reduce perceived abuse of filibusters on procedural motions and on motions to go to conference, but the Nevada Democrat could face reluctance to a plan that would have him make those changes using a simple majority vote. Their trepidation could increase the incentive for Senate leaders to cut a deal and avoid a toxic standoff in January.

Armed Services Chairman Carl Levin of Michigan and Sen. Mark Pryor of Arkansas this week have been among the most direct in expressing skepticism about that process, which could come through a parliamentary ruling from Vice President Joseph R. Biden Jr., who in theory would declare that the Constitution allows senators to set new rules at the start of the new Congress with a simple majority vote.