Two years to the day after President Obama signed it into law, the Affordable Care Act remains very much a work in progress.

The White House says its health-care reforms have improved the lives of millions, though the legislation’s most important provisions have yet to take effect. Detractors – a category that includes every GOP presidential hopeful – scorn Mr. Obama’s health reforms as Treasury-busting infringements on American freedoms.

Yet the most important question dealing with the ACA may be not how it’s doing, but whether it will survive. Next week the Supreme Court hears oral arguments on the constitutionality of the law’s lynchpin requirement that individuals carry health insurance.

“What’s at stake basically is whether or not the signature domestic achievement of the Obama administration is sustained,” says Russell Wheeler, a visiting fellow in governance studies at the Brookings Institution, in an online interview on the Affordable Care Act’s future.

Obama himself did not make a big live appearance promoting the ACA’s birthday. That could be in deference to the upcoming Supreme Court arguments, or it could be a reflection of the fact that polls show US voters remain split on whether the law’s passage was a good thing.

White House spokesman Jay Carney said Thursday it is “absurd” to think that Obama is distancing himself from the health law. Carney noted that Obama’s campaign has produced a video featuring Americans who have benefited from the ACA.

And the White House itself on Friday issued a report highlighting what it called the progress produced by the legislation.

Among its assertions: 2.5 million more young adults have health insurance, thanks to an ACA requirement that they continue to be covered on parental policies; 5.1 million Medicare recipients have saved $3.1 billion on prescription drugs because of increased ACA coverage limits; and insurance firms can no longer drop policy-holders who get sick if they made a mistake on their applications.

“And thanks to health reform, all Americans will have the security to know that you don’t have to worry about losing coverage if you’re laid off or change jobs, and insurance companies are required to cover your preventive care like mammograms and other cancer screenings,” concludes the White House report.

Meanwhile, Republican presidential frontrunner Mitt Romney blasted the Affordable Care Act on Friday.

“This presidency has been a failure. At the centerpiece of this failure is this piece of legislation, ObamaCare,” said Romney while campaigning in Louisiana.

Of course, Romney has his own health-care problem, in that while governor of Massachusetts he signed into law a health bill often credited with serving as the model for Obama’s national legislation.

In an opinion piece for USA Today this week, Romney outlined his own plan for national health reform, saying that among other things he would offer a tax benefit to individuals to buy health insurance on their own.

Romney added he would turn over responsibility for helping the poor, uninsured, and chronically ill to state capitals, instead of Washington.

“I favor giving each of the 50 states the resources and the responsibility to craft the health-care solutions that suit their citizens best,” wrote Romney.

Many of the most significant ACA provisions have yet to take effect, notes Kaiser Health News in a scorecard of what the law has delivered so far.

State-based exchanges, a kind of marketplace for individual insurance, aren’t supposed to be up and running until 2014, for instance. That’s when the US will start subsidizing the purchase of such policies for lower-income Americans.

Some parts of the bill that have already taken effect have exceeded expectations, according to Kaiser. The number of young adults whose coverage has continued on parental polices is almost twice the number predicted at the law’s passage, for instance.

Other provisions have underperformed. The White House estimated that 4 million small businesses by now would be receiving tax credits for their contributions to employee health plans. As of last November only 309,000 businesses had qualified for these credits.

Will all this be a moot point? It’s possible the ACA health care reforms will collapse if the Supreme Court strikes down the individual mandate at the heart of the bill. The requirement that individuals carry insurance makes economically possible such popular parts of the ACA as the provision that insurers cover people with pre-existing conditions.

Such a move by the Supreme Court would also mark a turning point in American constitutional law, according to Russell Wheeler of Brookings.

Get the Monitor Stories you care about delivered to your inbox. By signing up, you agree to our Privacy Policy

For decades many constitutional scholars have assumed that Congress has extensive powers to regulate US economic activity under the Constitution’s Commerce Clause. But if the justices reject the individual mandate, they’d be calling into question that interpretation of the law.

“If the court strikes down the individual mandate our constitutional law will take a 180 degree turn,” says Wheeler.