In many ways, the two plans are similar, but one key difference has opened another major rift within Congress. Republicans are ready to embrace Boehner's idea of addressing the debt problem in a two-step process, while Democrats want to vote on the issue only once before the 2012 elections, as Reid's plan calls for.
Despite all the disagreement, and the CBO's scrutiny, pressure is rising for both sides to find common ground and bring the issue to a conclusion. The US Treasury has warned that unless Congress votes to raise the current cap on federal borrowing by Aug. 2 (a vote lawmakers are linking to the deficit-cutting plans), the government will be unable to pay all its bills.
A default on US Treasury debt would be possible, and the downgrading of America's credit score all but assured, with negative consequences for interest rates and the economy.
In a closed-door meeting Wednesday, Boehner lobbied fellow Republican lawmakers in the House to support his plan.
An editorial in The Wall Street Journal echoed the speaker's case. "What none of these [Republican] critics have is an alternative strategy for achieving anything nearly as fiscally or politically beneficial as Mr. Boehner's plan," the conservative editorial page pronounced.
Backers argue that the Boehner plan would lead to more rigorous pressure to restrain federal spending than the Reid plan.
IN PICTURES: Who's who in the US debt crisis
Many analysts now see one of these competing plans, or some new hybrid of the two, as the most likely way to resolve the debt impasse by Aug. 2.
For his part, Reid responded to the CBO news Wednesday with a positive spin, saying it shows that "the Senate draft bill achieves $1.3 trillion more in deficit reduction than the Boehner plan."
But an analysis by the Committee for a Responsible Federal Budget, an independent organization focused on fiscal discpline, sees the two plans as "more similar than they are different."