Democrats are worried that after using all his chits to get barely enough votes for the strike resolution, Mr. Obama — whose negotiating skills are suspect to many on Capitol Hill — might then be too eager to cut a fiscal deal.

Especially worrisome would be if Republicans demanded, as the price for Syria, a rollback of the cuts to defense spending under sequestration, as the mandatory $1 trillion in budget cuts is known. There may be an appealing political case for this. Liberals are adamant that any changes to the automatic reductions must apply equally to domestic and military programs.

Immigration reform, which cleared the Senate handily, already faces a tough slog in the Republican-controlled House. As with the deficit and the debt-ceiling increase, the Syria debate and vote won’t make this any easier.

Final passage of comprehensive legislation, with a pathway to citizenship for undocumented immigrants, can be achieved only with a minority of Republicans. That would force the speaker to waive the so-called Hastert rule, which asserts that a bill can be considered only if it commands the support of a majority of the Republican caucus. Mr. Boehner will already have had to waive the rule for the Syria vote and might not be able to return to the well.