THE BIGGEST CHALLENGE for the next president will be putting the nation’s long-term finances on sounder footing. The failure to do so is the biggest shortcoming of President Obama’s first term. How he analyzes that failure, and how he would hope to do better in a second term, are key topics for the Democratic convention this week and the campaign that follows.

Mr. Obama took office in the midst of a financial crisis that demanded emergency measures, not attention to the long-term debt. After responding with a stimulus bill, he then chose to put his political capital into a bill intended to extend health-care insurance to millions of Americans and to begin to control health-care costs. He pledged, during the fight over that legislation, to pivot afterward to promoting fiscal soundness. But the pivot never materialized, with proposed compromises with Republicans in Congress dissolving in acrimony.

On Tuesday, Mr. Obama’s senior adviser Valerie Jarrett blamed Washington gridlock on Republican intransigence and said Mr. Obama’s failure was in not sufficiently enlisting public opinion to pressure GOP members of Congress, whose positions, she said, “ignored their constituents.” New York Sen. Charles Schumer, a leader of the Democrats, agreed that Mr. Obama had put too much energy into seeking compromise with Republicans.

“He didn’t go to the outside enough,” Mr. Schumer said. “He played too much of an inside game. He sat with Republicans around the table and said, ‘Let us compromise.’ ”

In a second term, Mr. Schumer said, “You will see a different kind of president in some ways. He will go to the public more.”

If these statements reflect Mr. Obama’s plans, we worry about the chances of more accomplishment in the second term than in the first. We agree that Republican bullheadedness, particularly in the doctrinaire opposition to revenue increases, has been a major obstacle to progress. If Mr. Obama wins, a crucial question will be whether defeat nudges Republicans to moderate their positions or whether they decide that nominee Mitt Romney was not ideological enough.

But Mr. Obama wasn’t faultless. Even when conservative Republicans such as Sen. Tom Coburn of Oklahoma signaled a willingness to deal, the president failed to show the leadership that might have made something happen.

Even if you buy Ms. Jarrett’s diagnosis, an “outside game” (to use Mr. Schumer’s terminology) is likely to fall short. Most members of Congress, thanks to skewed redistricting and voter self-sorting, live in safe districts, reasonably immune to pressure from the opposing party — and, indeed, are more fearful about a primary challenge from their party’s flank. More to the point, the nation’s voters are divided. A landslide or “mandate election” in November is unlikely because neither party enjoys a clear advantage.

Most fundamentally, any solution to the nation’s fiscal crisis is going to require compromise. No matter who is in charge, taxes will have to go up and entitlements will have to be scaled back. The math doesn’t work any other way.

These aren’t the kind of reforms that lend themselves to populist, call-your-congressman campaigns. They will be politically unpopular, and they can be implemented only if Republicans and Democrats hold hands and jump together. A public campaign could be helpful, if it’s designed to educate voters on why the nation’s future depends on painful trade-offs. But the will and fortitude to make those trade-offs will matter more.