On the debate stage, in interviews and at campaign rallies, President Donald Trump expresses the hope of many Republicans when he says he wants to end "Obamacare," or the Affordable Care Act, at long last.

Standing beside the president is U.S. Sen. Bill Cassidy, who Trump says is one of his go-to advisors on health care policy and is co-sponsor of a leading plan to replace the decade-old Patient Protection and Affordable Care Act. Perhaps no other issue more clearly separates the Baton Rouge Republican seeking his second term and his main Democratic challenger, Shreveport Mayor Adrian Perkins, than the future of the government program that has provided health care coverage to people who earn too much for Medicaid and too little to buy adequate insurance on the open market.

The future of the health law is not just at stake in the Nov. 3 election. It’s also on the docket Nov. 10 when the U.S. Supreme Court — apparently with a new 6-3 conservative majority after Amy Coney Barrett is to be confirmed — hears arguments about the Affordable Care Act’s constitutionality. Louisiana, through Attorney General Jeff Landry, is among the plaintiffs asking the high court to end the health law.

If the justices agree — a decision won’t come down until June — the responsibility of fixing, or not, the nation’s health care system falls to the U.S. senators and representatives being elected on Nov. 3.

In contrast to Cassidy, Perkins is a strong supporter of the Affordable Care Act, saying it has provided health insurance to 500,000 people in Louisiana and covered 1 million people in the state for their preexisting medical conditions.

“Their health care would be jeopardized if Cassidy had gotten his way and repealed the ACA,” Perkins said. “My No. 1 priority is to stop the assault on the ACA.”

Of course, Cassidy has a different view of his efforts.

“This is an issue incredibly personal to me,” said Cassidy, a charity hospital physician before going to Congress. “I care very deeply about this, and every piece of legislation that I have entered for health reform has always addressed the issue of preexisting conditions. I do think it is something we should address.”

Cassidy and South Carolina Republican Sen. Lindsay Graham co-sponsored the lead GOP plan to replace the Affordable Care Act. They couldn’t pass it in the Senate, however.

But Trump renewed support of the Cassidy-Graham measure late last year in his budget bill that sought to shift federal funding for Medicaid from a formula that pays expenses to “block grants” — funding that states can decide how to use and is based on the number of residents. Critics say that “block grants” could reduce funding for Medicaid — up to $1.5 trillion over the next eight years. They say it also could shortchange some state governments, leaving the states to pick up the difference. And many states, like Louisiana, won’t be able to afford their new share. This would require cuts in what procedures are covered and which residents are eligible to join.

The 900-plus-page Affordable Care Act, however, is more than insuring people who can’t afford adequate coverage. The law allows children to stay on their parents’ plans until age 26. It reduces prices for prescription drugs. It has sweeping rules and regulations about how insurance companies operate.

Funding is at the core of the health law and at the point of contention between Democrats and Republicans.

The health law relied on the healthy, mostly young people, to buy insurance in order to cover the increased costs for Americans, mostly older, who needed more medical attention. Republicans say that structure unfairly puts a financial burden on people having to buy a coverage they don’t currently need.

Perkins and other Democrats say the so-called individual mandate is an essential part of the legislation.

Perkins said the Cassidy-Graham bill “falls far, far short” of the Affordable Care Act.

“He promised to repeal and replace the ACA with something that’s better,” Perkins said. “What he put forth was a disastrous proposal. It would have stripped away health care from 500,000 Louisianians.”

The American Health Care Act, sponsored by Cassidy and Graham to replace the health law, dismantled a lot of that risk-sharing, which would lower policy prices for many people. It also gave state governments more say for how the coverage would be handled within their borders. The argument is that freed from government restrictions, insurers could offer more robust benefits at lower costs to most customers.

Critics were quick to point out that the language, depending on state rules, would allow insurance companies to charge the elderly more and customers with preexisting conditions a whole lot more — or even more jettison those with preexisting conditions.

Late-night TV host Jimmy Kimmel famously said Cassidy “lied to my face” with a promise that people with preexisting conditions would not be denied coverage or face higher premiums. Kimmel’s child has a heart condition. Cassidy replied that Kimmel didn’t understand the provisions.

Cassidy argues that provisions in the bill requires states applying for a waiver must “ensure that those with preexisting conditions have affordable and adequate coverage."

The preexisting conditions clause affects about 3% of Americans, only those on health law exchanges, Cassidy said. Customers covered by Medicare, Veterans Affairs, employer-sponsored insurance and other coverages needn’t worry about losing preexisting coverage.

Republicans have proposed replacement bills at least three times but were defeated by Democrats. “It tells me they would rather have a problem than have a solution,” Cassidy said. “We have legislation already lined up that if there is an issue for those 3% of Americans with preexisting conditions that we can pass the legislation, hopefully with Democrat support. It’ll be after the elections so they won’t have the same motivations to block it and we can protect those who have problems with preexisting conditions.”

Cassidy said the legislation used and expanded the rules of the Children's Health Insurance Program to handle the protections needed for preexisting conditions, which is a mechanism Democrats back, at least as it applies to CHIP.

The children's program provides low-cost health coverage to children in families that earn too much money to qualify for Medicaid. The program doesn’t exclude preexisting conditions, but children with serious medical conditions or disabilities could be moved to Medicaid or similar program depending on the state.

“They (critics) are saying it was not adequate, even though we used the CHIP program to expand coverage,” Cassidy said. “Predictably two weeks later or so, the Democrats voted unanimously to reauthorize the CHIP program so that which was inadequate when it was in my bill, now became something they voted unanimously for because it’s such a great program.”

A key point is the individual mandate, which is a financial penalty imposed on those who fail to obtain health insurance. A 5-4 Supreme Court in 2012 ruled that the penalty qualified as a tax and therefore was within Congress’ constitutional purview to enact. But inside Trump’s 2017 tax cuts was a provision that zeroed out the penalty.

That led Texas Attorney General Ken Patton, representing about a dozen Republican-led states, to argue in federal court that because the penalty was zero, the mandate could no longer be considered a tax. And if that is case, then the entirety of the health law is invalid as well goes their argument. Trump opted not to defend against the lawsuit, leaving California Attorney General California Attorney General Xavier Becerra to lead a coalition of states to oppose the lawsuit. Becerra's side counters that the Republican argument tortures the law, at best, but even if the Supreme Courts finds the provision unconstitutional, that doesn't nullify the rest of the Affordable Care Act.

The individual mandate is important, Perkins said, because “it was designed to make sure the pool was healthy enough to keep premiums low.”

“We need to make sure we keep what we have and strengthen it,” Perkins said.

Cassidy said, “Health care is 20% of our nation’s GDP. Most people making policy on health care have never even practiced medicine, and they don’t understand the dynamics of patients or insurance or doctors or hospitals; I do bring something unique to the conversation, and I think it shows in my legislation.”

Email Mark Ballard at mballard@theadvocate.com.