Rarely does a presidential administration face a week that could upend its authority and domestic agenda as drastically as this one.

The political world is eagerly awaiting not one but two Supreme Court verdicts that could reshape the political landscape for the Obama administration. One ruling will determine the fate of the Affordable Care Act, a piece of legislation that serves as President Barack Obama's signature domestic achievement, achieved a goal that has eluded Democrats for decades and ignited a furious partisan backlash.

Less heralded has been the court's consideration of an Arizona immigration law that crystallizes a national debate over the powers states should have to pursue undocumented immigrants. Multiple states passed laws imitating the Arizona law's strict enforcement provisions -- in particular, a measure that empowers police officers to check the immigration status of people they believe to be undocumented -- and the Department of Justice has intervened on the grounds that immigration enforcement is the province of the federal government, not the states.

Both rulings have the power to alter the contours of federal power, either in deciding whether the government can require people to obtain health insurance or in helping to set the balance between the federal government and the states in enforcing immigration law.

When Obama signed the Affordable Care Act, after a grueling journey through Congress that saw Tea Party protesters swarm Capitol Hill to register their outrage, there was little doubt from legal scholars that the bill passed constitutional muster. But Republican attorneys general sued, and the Supreme Court is set to decide whether the government can compel Americans to obtain health insurance.

Despite the extraordinary amount of political capital Obama expended to get the bill passed, the American public remains lukewarm in its reaction. Polls show that Americans favor provisions that allow children to remain on their parents' health insurance longer and that prevent insurance companies from refusing coverage to people with pre-existing conditions, but the individual mandate is unpopular.

Republicans have unified in their opposition to the mandate, casting it as an unconstitutional infringement on individual liberty. That critique helped drive the wave of election of 2010, which swept Republicans into power from Congress to statehouses around the country. Presumptive Republican presidential nominee Mitt Romney has vowed to repeal the law if elected.

If the Supreme Court strikes down the individual mandate, invalidating the linchpin of the Affordable Care Act, Obama will be campaigning under the shadow if his central accomplishement being declared illegal. But it would also put Mitt Romney and Republicans on the spot to offer an alternative.

Romney has articulated a plan in which people with pre-existing conditions would still be able to obtain insurance, but only if they had lost coverage after being fired or switching jobs. He has acknowledged the need to do something about uninsured Americans and has advocated redirecting federal Medicaid dollars to help states cover residents without insurance.

After Arizona passed the controversial SB 1070 in 2010, igniting protests and boycotts from opponents who said the law was a vicious exercise in racial profiling, several states followed suit with tough new laws of their own. Utah, Georgia, Alabama and South Carolina have put in place laws that mimic Arizona's guiding principle of attrition through enforcement -- basically, deporting more immigrants or making life hard enough that they leave.

The Obama administration contends that such laws usurp the federal government's authority, arguing that states cannot set enforcement guidelines that are out of sync with those adhered to by the federal government. And laws like Arizona's do conflict with the priorities set by the Obama administration -- look no further than the president's recent announcement that the government would stop deporting thousands of young undocumented immigrants.

A ruling that validates Arizona's efforts could embolden more states to pass their own stringent immigration laws, potentially giving rise to a national patchwork of states that enforce immigration laws with varying levels of intensity. It will also shape the fate of laws in states like Alabama, whose partially suspended law is awaiting further rulings pending the Supreme Court's Arizona decision.