The GOP megabill has new tax breaks aimed at low- and moderate-income households, and spending cuts that could make it harder for some to receive public assistance or hold onto health insurance.

Against odds that at times seemed improbable, the president achieved his goal of celebrating a historic — and divisive — legislative victory in time for the nation's birthday, which also was his self-imposed deadline for Congress to send the legislation to his desk.

The GOP tax bill is deeply unpopular, but Republicans still have an opportunity to influence public perception because many Americans know little about it.