Judge Andrew Napolitano said the Trump administration's push to overturn the Affordable Care Act could be "politically catastrophic" for the Republican Party.

Justice Department attorneys last week filed a letter with the U.S. Court of Appeals for the Fifth Circuit in New Orleans asking to effectively strike down the ACA -- also known as ObamaCare -- in its entirety, agreeing with the landmark ruling made by a federal judge in Texas last year.

U.S. District Judge Reed O’Connor ruled last year that ObamaCare is no longer constitutional because the Republican tax overhaul eliminated the health care law’s penalty for not having health insurance.

Multiple congressional Republicans expressed frustration with the Trump administration for going after ObamaCare, particularly since it came during what might have been the best week of Trump's presidency.

"Politically for the Republicans, it's an enormous problem," Napolitano said on "America's Newsroom" Monday. 

He explained that he agrees with the administration that the ACA is unconstitutional, but if the courts rule that it is indeed unconstitutional, then that could create an immediate vacuum in the American health care system and toss millions of people off health care plans because of pre-existing conditions.

"You have 21 million people in the United States receiving government-subsidized health insurance as a result of ObamaCare. You're gonna take that away from them? It'll be politically catastrophic," Napolitano said.

He said that's why many Republicans actually are hoping the Trump administration loses this legal battle and the statute is upheld.

"Because they don't have anything to replace it. And they can't physically get something done between now and the 2020 campaign."

Watch the clip above, and sign up for Fox Nation to get more legal insight from the judge on "Liberty File."

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