The departure of a member of the “Gang of Six” initially seems like it would be a major setback to the process of reaching an agreement between the two parties on reducing the long-term national budget deficit.

But the prospect of a deal remains as likely as it did before Sen. Tom Coburn (R-Okla.) decided to leave the talks: President Obama and either House Speaker John A. Boehner (R-Ohio) or Senate Minority Leader Mitch McConnell (R-Ky.) probably will need to hash out and sign off on any agreement for it to be accepted by members of both parties in Congress.

The Gang of Six was an unusual coalition that included a liberal Democrat (Sen. Richard J. Durbin of Illinois) and until Wednesday, one of the most conservative Republicans in Congress (Coburn). But Obama and congressional Republicans could have ignored the group’s recommendations, just as they did the findings of last year’s bipartisan deficit commission.

Both parties are aware of what a deal would have to include to receive bipartisan support: reductions in long-term spending on Medicare and Medicaid; cuts in domestic and defense spending; and either tax increases or the elimination of some popular tax breaks. But almost no leading Republican has joined Coburn in saying he would support tax increases. Liberal Democrats are calling on Obama to back an agreement only if it leans heavily toward tax increases and away from spending cuts, an approach that would receive little Republican support.

To reach a deal, lawmakers in both parties will have to vote for provisions they oppose, something that usually happens only after being pushed by party leaders.

Obama and McConnell’s embrace of a tax deal in December helped it get bipartisan support, even as some Republicans opposed expanded unemployment benefits and Democrats didn’t like extensions of tax cuts for wealthy Americans.

“Gang of Six” or not, such leadership will be needed again for an agreement on reducing the deficit. What remains unclear is whether Boehner, McConnell or Obama will provide it.

Obama today

The president will speak to graduates of the Coast Guard Academy in New London, Conn., then head to Boston for a fundraising event for his 2012 reelection campaign.