It was a surprise finish with a Hollywood-like twist.

Few could have predicted that in the climactic moment of this national debate, conservative Chief U.S. Supreme Court Justice John Roberts would be the one announcing a majority decision upholding the central tenets of the health care reform law. Meanwhile, Justice Anthony Kennedy, who was expected to be the swing vote, would be announcing a dissenting opinion that essentially accused the majority of judicial activism.

But that's how history unfolded Thursday in a landmark decision upholding the central provisions of the Affordable Care Act, thus ensuring access to health care for about 30 million uninsured Americans.

Here's the crux of this 5-4 ruling: The so-called individual mandate passed constitutional muster not because it is a command but because, in the eyes of the court, it is a tax.

Roberts wrote for the majority that the requirement that Americans buy health insurance would not survive constitutional scrutiny if it were evaluated solely on government's specified authority to regulate commerce.

"The federal government does not have the power to order people to buy health insurance," Roberts wrote.

But given that the penalty for noncompliance is a fine, the court found it can be evaluated under Congress' authority to invoke a tax.

"The Affordable Care Act's requirement that certain individuals pay a financial penalty for not obtaining health insurance may reasonably be characterized as a tax," Roberts wrote. "Because the Constitution permits such a tax, it is not our role to forbid it, or to pass upon its wisdom or fairness."

Meanwhile, the court frowned upon part of the law that expanded Medicaid but ultimately ruled the expansion could move forward so long as the federal government did not threaten to withhold a state's entire Medicaid allotment if it chooses not to participate in the law.

Roberts was joined by Justices Sonia Sotomayor, Stephen Breyer, Ruth Bader Ginsburg and Elena Kagan in the decision.

Meanwhile, Kennedy voiced a strong dissent along with Justices Samuel Alito, Antonin Scalia and Clarence Thomas. "In our view, the act before us is invalid in its entirety," he said in court.

Ultimately, the American public will have the final say on whether the law will stand. Former Gov. Mitt Romney, the presumptive GOP presidential nominee, has vowed to repeal "Obamacare" if he wins the election in November. To do so, he would also need Republicans to gain control of the U.S. Senate and win enough seats to remain in the majority in the House.

Meanwhile, President Barack Obama can use this legal victory as fodder for his bid for re-election, this being the signature legislative achievement of his first term.

Ultimately, however, this should be viewed less as a victory for lawyers or lawmakers than it is for countless Americans who have fallen victim to the many hidden traps in our broken system of health care.

Once the law fully takes effect in 2014, low- and middle-income Americans, many of whom lost their health insurance along with their jobs, will be able to buy coverage at affordable prices. Insurance companies will no longer be able to deny coverage for pre-existing conditions nor will they be able to charge more once health problems develop. And parents of adult children may keep their children on their policies until the age of 26, assuring they won't be without a safety net.