For all their differences on "Medicare for All," Democrats will have a chance to rally around the 2010 health care law this week.

The U.S. Court of Appeals for the 5th Circuit will hear oral arguments in the high-profile Texas v. Azar lawsuit on Tuesday, which could spell the future of the health care law and become a major issue in the 2020 election cycle.The hearing comes as Democrats have been debating their next steps beyond the 2010 law  and the role of private insurance in the nation's health care system. While those differences have been on stark display since last month's Democratic presidential debates, a lawsuit threatening to overturn the law could be unifying for Democrats trying to draw comparisons with the Trump administration."The difference on health care are Democrats who want to expand coverage and decrease costs and Republicans, whose policies would get rid of coverage, lower coverage for millions of people and increase costs," said Brad Woodhouse, the executive director of Protect Our Care, a group that advocates for the 2010 health care law.

Judge Reed O'Connor, a federal judge for the Northern District of Texas, ruled in December that the 2010 law should be invalid after the 2017 Republican tax overhaul ended the penalty for not having health insurance coverage for most Americans. The decision was stayed pending appeal, so the law remains in effect.

Texas and a coalition of Republican-led states filed a lawsuit last year seeking to overturn the law, arguing that without the so-called individual mandate, the law should not stand. The Trump administration last year declined to defend two key parts of the law that ensure people with preexisting health conditions cannot be denied or charged more for health insurance, saying they were inseverable from the coverage requirement. The administration expanded that position in March, calling on the 5th Circuit to confirm O'Connor's ruling.

The 5th Circuit denied a request from the Texas-led coalition last week to delay oral arguments in the case after the court asked both sides to file supplemental briefs regarding the standing of California and its coalition and of the U.S. House of Representatives to defend the law.

Although a federal judge said the law should be struck down, Woodhouse said he didn't think enough Americans are even aware of the pending lawsuit.

"When we get into political season, there's going to have to be money spent to remind people on television about this lawsuit," he added.

A key political issue

The legal challenge hasn't been a primary focus for most Democrats since March, but could play a major role in the party's 2020 strategy, as it did last year when Democrats won back the House for the first time since 2008. Democrats attribute that win to campaigning on the health care law's protections for people with preexisting conditions as the Trump administration fought to undermine them in court.

"The number one issue was health care because people truly believe and understand that this is personal for them and their families," said Sen. Debbie Stabenow, D-Michigan. "They are extremely upset that this is viewed as something that's a political football by Republicans in this administration."

Should the lawsuit reach the Supreme Court, a ruling could come next summer - in the heat of the 2020 campaign, in which polls show health care will be a key issue for voters.

Although the administration has called for the entire law to fall, and President Donald Trump has promised a new health care plan, a Kaiser Family Foundation poll found that 68 percent of people do not want to see the Supreme Court overturn protections for people with preexisting conditions.

People may become more aware of the lawsuit should it reach the Supreme Court, especially because legal experts on both sides of the aisle have warned it is unlikely to be successful, said Robert Blendon, a political science professor at Harvard University who has focused on the health care law.

"If it actually was actually threatening the ACA, it would change the whole discussion," he said.

If the case does reach the Supreme Court, then Democratic presidential candidates may start raising the idea of emergency legislation to preserve parts of the law while debating their own health care agenda, he added.

Former Rep. John Delaney of Maryland, who is seeking the Democratic presidential nomination, said in New Hampshire last week that if elected, he would want to first focus on ways to stabilize the law, such as setting up a reinsurance program or a public option, and then have a longer debate about how to move beyond the law with his own plan to reach universal coverage. He criticized progressives for minimizing the health care law by saying it does not go far enough.

"They're taking Obamacare and they're putting it under this disparaging, centrist moderation, incrementalism. I'm like, what are you talking about?" he said.

Some Democrats warned that having too heated a debate among themselves and not calling attention to the differences between the parties could come at their peril. Sen. Christopher S. Murphy, D-Connecticut, said he expects Democrats will debate their individual health care plans throughout the primary, but warned them not to focus on that so much that candidates don't explain to voters how Trump and his administration are seeking the roll back the health law.

"If he gets a second term, then it's not time well spent," Murphy said.