One needs to be careful not to unintentionally damn Mr. Obama and the Democrats with faint praise; yes, they got a lot done, but all of the measures they passed were quite popular. Once the Republicans take over in the House, Mr. Obama will be engaged in some big showdowns with them over issues like the budget and his health care plan. Mr. Obama will be fighting from a defensive posture on health care, which remains unpopular with the public. How the public feels about the budget, where it has little faith in either party, is less clear.Ultimately, however, Mr. Obama is more popular than the Republican Congress — an advantage that Bill Clinton did not have after 1994, nor Ronald Reagan after 1982. With the equally unpopular Democratic Congress largely being marginalized, that may work to his advantage. And — although I hesitate to endorse such a wishy-washy concept — the Democrats’ successes during the lame-duck session may provide him with some “momentum” headed into these battles, which will begin very early in the new Congress.