A federal judge has begun hearing arguments on Senate filibuster rules this week in a lawsuit brought by critics, including Minnesota Democrat Keith Ellison, who argue the practice has held up immigration reform in Congress.

 

Several groups, including Common Cause and several Democratic lawmakers, argue that Congress is constitutionally required to pass legislation by a simple majority vote, instead of a 60-vote supermajority that can hold up debate indefinitely.

 

The challenge is now before U.S. District Judge Emmet G. Sullivan in Washington, D.C.

 

Senate attorneys argue that the Constitution’s provisions for separation of powers prevent the courts from intervening in the internal deliberations of Congress. All previous challenges have failed.

 

Senate Democrats, who control the Senate, have vowed to reform the filibuster rule when a new Congress convenes in January.

 

Defenders of the filibuster (usually the minority party at any given time) say it protects the rights of minority parties.