The rules requires 60 votes to end the speeches of a filibuster, the threat of which has become so common that congressional leaders assume most bills cannot pass the 100-member Senate with a simple majority of 51 votes.
While Democrats hold majorities in the House and Senate, the 60-vote threshold for action in the Senate has allowed Republicans to block much of President Barack Obama's agenda.
"Even when a party loses (an election), it too easily can prevent the majority elected to govern from legislating," Sen. Tom Harkin, D-Iowa, told Sunday's Los Angeles Times.
Harkin wants to reduce the number of votes needed to end debate from 60 votes on the first attempt, to 57 votes if another vote is held two days later, to 51 votes if debate drags on, the Times reported.
Few senators, however, will be willing to change rules that gives enormous leverage to either party when it finds itself in the minority, Donald Ritchie, the Senate's historian, said.
"It's a real obstacle to getting much done, but it's ingrained into the Senate," Ritchie said.