All 47 Senate Republicans, seeking fiscal discipline in big-spending Washington, proposed on Thursday an amendment to the Constitution that would require a balanced federal budget.
A number of such efforts have failed over the years. But backers are hopeful this one may succeed amid an unprecedented push to trim the federal deficit, projected to hit $1.4 trillion this year.
"It's long past the time that we stop spending money we don't have," said Senator Lamar Alexander, a member of Republican leadership. "Requiring that we balance our national budget is a logical step in that direction."
To become law, proposed constitutional amendments must be approved by two-thirds majority votes in the House of Representatives and the Senate, and then ratified by three-quarters of the 50 states.
"The whole thing is a long shot," said Dan Ripp of Bradley Woods, a private firm that tracks Washington for investors.
"The framers (of the Constitution) designed the amendment process to be difficult on purpose," Ripp said.
Under the Republican proposal, the requirement for a balanced budget would go into effect five years after ratification.
It would permit limited exemptions, such as during a time of war. The proposed amendment would also require a two-thirds vote in the House and Senate to raise taxes.
Since the Constitution was ratified in 1789 as the supreme law of the land, just 27 amendments have been approved, the last in 1992.
A balanced budget amendment passed the Republican-led House in 1995, but fell short in the Republican-led Senate.
Democrats now control the Senate, 53-47. So far, none of them have embraced the Republican balanced-budget proposal.