The one-two punch of complicated health-care reform legislation and impenetrable legal arcana may seem better suited to a university law seminar than a "political and constitutional blockbuster." But the sharply divided Supreme Court practically guaranteed political fireworks by agreeing on Monday to decide the constitutionality of President Obama's signature Affordable Care Act (ACA) right in the heat of the 2012 election. Here, a guide to the Supreme Court's "biggest case of the century":

What's the time frame for the ACA ruling?
The Supreme Court will hear 5 1/2 hours of oral arguments over two days in March or April 2012, and hand down its decision before the end of June — right in the midst of the presidential campaign. 

How split is the court?
Right down the middle. Justices Ruth Bader Ginsberg, Stephen Breyer, Sonia Sotomayor, and Elena Kagan are liberal, and widely expected to support Obama's law. Justices Antonin Scalia, Clarence Thomas, Samuel Alito, and Chief Justice John Roberts are conservative. Swing voter Anthony Kennedy could go either way — and is often the court's deciding vote.

What exactly is the court deciding on "ObamaCare"?
Four things, really. First, whether the law can even be challenged, or if the Anti-Injunction Act — which prevents taxpayers from challenging a tax or penalty before it goes into effect — pushes any legal challenge back to 2015, after the individual mandate (which requires Americans to obtain health insurance) kicks in. Then, the justices will decide if the individual mandate is constitutional. If the mandate is ruled unconstitutional, the court will decide whether that invalidates the entire ACA. Finally, to the surprise of just about everybody, the justices agreed to decide if the law's expansion of Medicaid is an infringement on states' rights.

What have lower courts ruled?
Four federal appeals courts have weighed in on the law, with two — in Washington, D.C., and Michigan — upholding the ACA's individual mandate, the Atlanta-based 11th Circuit court striking it down (but arguing that the lack of a mandate didn't bring down the rest of the law), and the Virginia-based 4th Circuit citing the Anti-Injunction Act to dismiss the case. The Supreme Court agreed to hear the 11th Circuit appeal. None of the lower court judges has endorsed the Medicaid part of the case.

What's the Medicaid issue about?
The ACA extends Medicaid — a state-administered health care program largely paid for with federal funds — to include low-income adults. Republican officials in 26 states argue that that amounts to federal coercion, since states that fail to comply will lose all their Medicaid funding. Since no lower court judge bought that argument, it's a real stunner the Supreme Court took up the issue. Well, it's probably out of courtesy to the 26 states, says Ilya Shapiro at Cato @ Liberty. But "as a practical matter, this could be a bigger deal than the individual mandate." Congress attaches "plenty of strings to the grants it gives states," and if the justices side with the 26 states, it could cripple Congress' future ability to tie the money it doles out to policy issues.

What are the arguments for striking the law down?
The central question with the individual mandate is whether the Constitution's Commerce Clause allows Congress to regulate not just interstate economic activity, but also what opponents call economic "inactivity" — in this case, not buying health insurance. Does punishing Americans for not purchasing health insurance lie outside Congress' power "to regulate commerce"? Opponents say the ACA is a massive overreach of that constitutional authority.

And for upholding it?
The "key flaw" in the opponents' case is the "failure to recognize that literally everyone at some point will use the health care system," so "everyone is already making an 'affirmative' active economic choice to purchase health insurance or to self-insure," says Erwin Chemerinsky in the Los Angeles Times. Unless the conservative justices indulge in partisan politics, "this should be an easy case to predict — the law is clearly constitutional." It's also a good first step to "reduce medical costs and provide health insurance to all Americans," says the San Jose Mercury News in an editorial. Besides, "the most recent polls indicate a majority of Americans now support moving forward with the reforms."

Any guesses on how the justices will rule?
There's no consensus among court-watchers. ACA opponents should be cheered by the "whopping 5.5 hours of oral argument," instead of the typical one hour, says Orin Kerr at The Volokh Conspiracy. Clearly, at least some justices are taking the challenges very seriously. "Kennedy will be the decider," says Harvard's Noah Feldman at Bloomberg, and he'll probably be persuaded that it's best to kick the issue down the road, or even uphold the law. "You don't need a law degree to know how the Supreme Court is going to vote," says Jeffrey Toobin at The New Yorker, you "just know which way the wind is blowing." If "Obama looks like a lame duck" when the court decides the case, Kennedy will be more likely to undo the president's signature issue. If Obama "looks like a winner," "ObamaCare" will probably win, too.

Sources: Bloomberg View, Cato, CNN, Los Angeles Times, New Yorker, New York Times, San Jose Mercury News, SCOTUSblog, Slate, Wall Street Journal, Washington Post, Volokh Conspiracy