The Supreme Court on Monday opens one of its most anticipated terms, in which the justices could strike down President Obama's healthcare law, empower local police to arrest illegal immigrants, and declare an end to affirmative action in colleges and universities.
The cases coming before the court "address some of the central issues facing the country," said former Solicitor General Walter Dellinger. The clashes over healthcare and immigration "are not mere lawyers' issues, but fundamental questions about how the country is governed."
"By June of 2012, this may prove to be among the most momentous terms in recent decades," said Elizabeth Wydra, chief counsel for the Constitutional Accountability Center in Washington.
The justices will decide over the next few months whether to hear the cases. If they do, rulings will be handed down by late June, just as the presidential campaign moves into high gear.
Most legal scholars predict the justices will not steer clear of the controversies. "The fact that the issues are politically charged and it is an election year won't cause them a moment of hesitation," said Harvard Law School professor Richard Lazarus.
The court has five Republican appointees and four Democratic, and in major cases that divide along ideological lines, the conservative wing prevails most of the time.
The major issues:
Immigration: Republican Arizona Gov. Jan Brewer wants the court to rule that states and their police can question and arrest illegal immigrants. Lower-court judges blocked Arizona's law from taking effect, saying the federal government has exclusive control over immigration.
Last week, though, a judge in Alabama cleared parts of a similar state law to go into effect there. This legal split means the high court will probably move soon to resolve the state-versus-federal dispute over who can enforce immigration laws.
A ruling upholding the Arizona immigration law would encourage more states and cities to adopt measures that crack down on illegal residents.
Affirmative action: In September, two white students turned down for admission by the University of Texas appealed to the high court, arguing that officials wrongly used race to favor minority applicants at the expense of whites and Asian Americans. Their appeal urges the court to outlaw the use of race as an admissions factor in public universities, just as the court, in a 5-4 decision, barred public schools from assigning students based on race to achieve classroom diversity.
Healthcare: Republican officials from 26 states are urging the justices to rule that the Democratic-controlled Congress overstepped its power by regulating the health insurance market. They want the court to void the requirement that all Americans must have health coverage by 2014 or pay a tax penalty.
The healthcare case could be a defining moment for Chief Justice John G. Roberts Jr. Beginning his seventh year as the court's leader, Roberts comes from a conservative tradition that believes in limits on the powers of the federal government and a limited role for judges in deciding highly political questions. Those two principles are in conflict in the healthcare case.
On the one hand, a high court ruling upholding the insurance mandate would suggest the federal government could tell Americans what products they must buy. Could Congress require Americans to buy American-built cars or to pay a tax for not joining a health club? Florida Atty. Gen. Pam Bondi, a Republican, said last week that striking down Washington's requirement to buy health insurance would "define the boundaries of Congress' power" and "defend Americans' rights and freedoms."
But a decision to throw out the law would be the court's most dramatic veto of major national legislation since justices struck down President Franklin D. Roosevelt's first New Deal measures in 1935. Since then, generations of law students have been taught that in matters of economics and business, Congress makes the law and the court stands aside.
If the court were to void the individual mandate, it would put healthcare reformers in a box. They could go back to Congress and seek a fix, but Republican lawmakers are not likely to vote for more taxes to make up for the loss of revenue from those who do not want to buy insurance.
From the other side, outraged Democrats and liberal activists would brand it conservative judicial activism if a narrow right-leaning majority were to throw out a national healthcare overhaul that was championed by the president and passed by the House and Senate.
Political activists on the left have not forgiven the Roberts court for its 5-4 ruling last year that struck down the long-standing bans on corporations and unions spending freely on election campaigns. A ruling against the healthcare law could make "judicial activism" a political rallying cry for the left, just as it has been on the right for a generation.
Healthcare experts are also watching a major Medicaid case from California to be heard by the high court on Monday. It will decide whether courts can stop states from slashing their payments to doctors, hospitals and pharmacists who serve low-income patients.
The right to privacy is on the court's docket in November. New tracking technology, including GPS, allows police to follow a car for weeks or months. The government argues that since no one has a right to privacy when traveling on a public street, authorities can secretly attach a GPS device to a car and monitor its movements — all without obtaining a search warrant.
Dellinger, who represents the defendant in the case, said it "may be the most important privacy case in decades because it is the court's opportunity to address technology like we have never seen before."