Earlier this week, the Justice Department issued a letter agreeing with a district court's ruling that the Affordable Care Act is unconstitutional. Now the case against the health care law, which is also known as Obamacare, will likely work its way to the Supreme Court.

President Donald Trump reinforced the Justice Department's stance at the White House yesterday, saying, “If the Supreme Court rules that Obamacare is out, we'll have a plan that is far better than Obamacare." He has not provided further details on his administration's plan.

Joining Boston Public Radio to weigh in on this topic was medical ethicist Arthur Caplan . Caplan is the Drs. William F. and Virginia Connolly Mitty Chair and director of the Division of Medical Ethics at NYU Langone Medical Center, as well as the co-host of the "Everyday Ethics" podcast.

"It would completely upend health care in the US," Caplan said.

Caplan said the move could throw out popular tenets of Obamacare, including protections for patients with preexisting conditions and the provision that children can stay on their parents' health care plans until age 26.

"We have this restriction that says under Obamacare, you can't preclude people because of preexisting conditions, [and] that includes pregnancy," Caplan said. "That would go out the window, and the insurance company could charge anything they wanted for people with preexisting conditions, or their kids, or not take them at all."

Politically speaking, that could spell trouble for Republicans, Caplan said.

"Trump's triumph of getting vindicated [by Mueller] lasted exactly one day, because this will give the Democrats back the high ground," he said.

The day after the announcement, Trump told a group of Republican lawmakers, "The Republican Party will soon be known as the party of health care. You watch."

"I think that's true — but not in the way he means it," Caplan said.