U.S. House Speaker Nancy Pelosi, a Democrat from California, center, speaks during an event with House and Senate Democrats on protecting the Affordable Care Act outside the Supreme Court Building in Washington, D.C., on Tuesday, April 2, 2019.

Obamacare will get its day in court — again.

A federal appeals court in New Orleans will hear 90 minutes of oral arguments on Tuesday afternoon over the constitutionality of the Affordable Care Act, the landmark health-care legislation passed nearly a decade ago under President Barack Obama, in a case that could have sweeping ramifications for the nation's health system.

It's the latest in a long line of attempts to dismantle the law, known as Obamacare. To date, the legislative and legal attempts have been met with little success. Congress, despite two years of GOP control and a Republican president, has not repealed the law. And the Supreme Court has upheld its core provisions twice.

But Texas and a group of other Republican-led states have not given up.

Late last year, the states succeeded in getting a federal judge in Texas to strike down the law, though that ruling has not been implemented. And on Tuesday, defending that ruling, they will face off against Democratic-led states and the House of Representatives in arguments before a three-judge panel of the U.S. 5th Circuit Court of Appeals.

The Republican states are joined by the Trump administration. The Department of Justice, after first asking the court to only invalidate certain provisions of the Affordable Care Act, is now asking the court to do away with the measure in its entirety.

Experts say that if the Fifth Circuit invalidates Obamacare, there is virtually no telling what the immediate result would be. Though, if the court strikes down the law, the decision will almost certainly be reviewed by the Supreme Court.

"The whole health-care system would be in disarray," said Aviva Aron-Dine, the vice president for health policy at the Center on Budget and Policy Priorities. "It really would just throw things into chaos."

At stake is the health-care coverage of about 20 million people, protections for those with pre-existing conditions, and the expansion of Medicaid, which provides coverage to low-income adults.

The outcome could affect the presidential race. A decision could come by fall, potentially igniting new arguments over health care in the midst of the 2020 campaign. The median time between oral arguments and a ruling is about two months, according to Fifth Circuit data.

Democrats are already poised to make health care a central issue, and an adverse ruling could fuel the party's efforts. Democratic candidates referenced health care more than any other issue during the 2018 midterm races that saw the party seize control of Congress's lower chamber.

Republicans have vowed to replace Obamacare with health-care legislation of their own, but the party has not been able to form a consensus around any particular bill.