The group's plan would cap income tax rates at no more than 29 percent, and the middle class would be permanently exempted from the alternative minimum tax. But net revenue would increase by shrinking deductions and tax loopholes.
The group had appeared all but left for dead after Coburn left it earlier this year and talks stalled. But his return — and the hunger of Senators for a serious effort at reaching a big deal — revived it.
Coburn said it looks as if about 60 Senators are likely to back it.
Besides Coburn, Durbin and Warner, Senate Budget Chairman Kent Conrad (D-N.D.), Sen. Mike Crapo (R-Idaho) and Sen. Saxby Chambliss (R-Ga.) are original members of the gang of six.
Chambliss said the group has basically agreed to the package, with the exception of a few small details. He said he wants to brief House lawmakers in hopes of enlisting their support. Chambliss is a close friend of Boehner's.
Several Senators from both parties spoke positively of the plan to reporters after the meeting.
"This is the sort of big, balanced and bipartisan package that we need to move the country forward," Coons said.
He added, "If Sen. Durbin and Dr. Coburn can both endorse it, this may be just the tough discipline fiscally and the balanced path forward that we need."
The group's plan includes an upfront down payment reducing the deficit by $500 billion and requires nine Senate committees to produce legislation implementing the rest of the deal within six months, according to an outline obtained by Roll Call.
The plan also creates strict new spending caps that would require a 67-vote supermajority in the Senate to breach and shrink annual deficits to less than 2 percent of the gross domestic product from about 10 percent this year.
And the plan tackles Social Security, calling for reform that would ensure the program's solvency for 75 years and plow any savings back into the program. It would be handled on a separate legislative track, but the overall package would not move forward without it. Of note, the plan includes several enforcement mechanisms that would force spending cuts if committees fail to produce legislation.
Meredith Shiner, Humberto Sanchez and Ambreen Ali contributed to this report.
This article updates the print version to include comments from House Majority Leader Eric Cantor and the results of the Tuesday evening House vote on the Cut, Cap and Balance measure.
Former Sen. Scott Brown, R-Mass., candidate for U.S. Senate in New Hampshire, holds his hand over his heart during the singing of the national anthem as he waits to take the stage for his town hall campaign rally with Sen. John McCain at the Pinkerton Academy in Derry, N.H., on Monday, Aug. 18, 2014.