The Supreme Court announced this week that it will hear some of the constitutional challenges to President Barack Obama’s signature health care law, the Affordable Care Act (ACA).

The court’s decision to act came as no surprise to court-watchers, but what was unexpected were the range of issues the court asked the litigants to argue and the amount of courtroom time the court will devote to the oral argument.

When the Supreme Court decides what cases to accept, a few factors stand out as most important: If the Circuit Courts of Appeals are divided, so that the Constitution means one thing in Florida and something else in Texas, the Supreme Court is almost obliged to step in to settle the dispute.

If the controversy deals with an issue of substantial importance to the lives of many people, the Supreme Court is likely to intervene. And when the lawyer representing the United States, the solicitor general, asks for the court’s involvement, the justices often take action.

All three of those factors are present here, which is why the Supreme Court’s decision to take up the constitutionality of the ACA was expected.

One surprise, though, was the court’s decision to set aside five and a half hours, across two days in March, to accommodate the oral argument.

Usually, the court gives each case only one hour’s time for a hearing. Occasionally, a very important or complex case will get two hours. Five and a half hours for challenges to a single law is almost unprecedented in the modern history of the Supreme Court.

The amount of time being devoted to the issue has cheered opponents of the ACA. They surmise that the justices would not have allotted an extraordinary amount of time to the argument if they did not recognize that the act raises extraordinary constitutional questions, as they contend.

Opponents of the act, however, should not read too much into the allotment of time. That the justices recognize that their decision will stand as a landmark does tell us what constitutional “territory” it will mark. A decision to ratify and expand the New Deal vision of an activist government is just as certain to make the casebooks as a decision to reaffirm the Constitution’s textual commitment to limiting the national government’s powers.

The other surprise was the court’s choice to take up four legal questions. That the court would consider the “individual mandate” was expected.

Opponents of the ACA insist that the power of Congress to regulate commerce among the states cannot include the power to require individual persons to engage in commerce by purchasing insurance products from private businesses, as the mandate requires. With the Circuit Courts of Appeals divided on this fundamental question, the Supreme Court eventually will need to settle the issue.

The court also took up a second substantive issue, pressed by 26 Republican state officials: That the expansion of Medicaid coverage required by the act is unconstitutional because it “coerces” the states.

Basically, the ACA tells the states they must structure Medicaid the way Washington tells them to do, or forfeit all of the Medicaid funding they receive from Washington, which can amount to 20 percent of a state’s budget. The states contend that, in practice, they have no choice but to accept the money.

None of the lower courts has sided with the states on this issue, but the Supreme Court recently ruled to protect the decision-making authority of states from federal coercion, and if it did rule for the states on this issue, the consequences for other federal programs could be very far-reaching.

The other two issues are both technical, but no less important for that. The court will consider whether invalidating any part of the act requires them to annul the whole thing, or whether the parts are “severable.” And it also will consider the possibility that no one has the right to sue to challenge the act until after it has gone into effect and someone has been forced to pay a tax penalty for non-compliance.

A decision on the substantive merits is expected in late June, but a decision not to decide until the law has gone into effect is not out of the question and might well be their best option. Ruling on the merits now would inject the Supreme Court into the middle of a national election; waiting until later would let the people decide by making the election into a referendum on the merits of the health care law.

Joseph R. Reisert is associate professor of American constitutional law and chairman of the department of government at Colby College in Waterville.