for U.S. Congress

WASHINGTON — When Congress handily passed a bill to set payroll tax rates, jobless benefits and Medicare doctors’ fees for the next two months, it seemed to end an epic political struggle between President Obama and Republicans on Capitol Hill. In fact, that was just the beginning.

Every issue in dispute remains unresolved, waiting to be addressed when Congress returns next month for an election-year session in which agreements could be even more elusive.

Basically, the new law, signed on Friday by Mr. Obama, preserves the status quo through February, so House and Senate negotiators can try to reach longer-term agreements on the Social Security payroll tax, unemployment insurance, Medicare and a few other issues, like the shape of the welfare program that provides cash assistance to more than 4.6 million poor people.