NEW YORK (Reuters) - Two Republican state attorneys general on Monday urged a federal appeals court to uphold the Obamacare federal healthcare law, saying that striking it down would be disruptive for patients, doctors, insurers and employers.

FILE PHOTO - A sign on an insurance store advertises Obamacare in San Ysidro, San Diego, California, U.S., October 26, 2017. REUTERS/Mike Blake

The attorneys general of Ohio and Montana submitted “friend of the court” briefs to the 5th U.S. Circuit Court of Appeals, which is expected to review a December ruling by U.S. District Judge Reed O’Connor in Fort Worth, Texas, striking down the Affordable Care Act, popularly known as Obamacare.

Dozens of patient and healthcare industry groups, including the American Medical Association, American Hospital Association, American Cancer Society and seniors advocacy group AARP also filed briefs in support of the law.

The briefs come less than a week after the U.S. Department of Justice, in an unexpected legal maneuver, said the entire healthcare law should be invalidated. Previously, President Donald Trump’s administration had said portions of Obamacare should be struck down and others should survive, including a state-led expansion of the Medicaid health insurance program for the poor.

The 2010 law, seen as the signature domestic achievement of Trump’s Democratic predecessor, Barack Obama, has been a flash point of American politics since it passed, with Republicans including Trump repeatedly attempting to overturn it.

Democrats made defending the law a powerful messaging tool in the campaign for the November elections, in which they won a decisive 38-seat majority in the U.S. House of Representatives.

The House submitted a filing last month to the appeals court in support of the law, as did a group of 17 mostly Democratic-led states including California and New York.

The lawsuit that led to the Texas ruling was brought by a coalition of 20 Republican-led states including Texas, Alabama and Florida.

It centered on the law’s so-called individual mandate requiring individuals to buy health insurance or pay a penalty. In 2012, the U.S. Supreme Court rejected a challenge to the mandate, ruling that the penalty was allowed through Congress’ power to tax.

In late 2017, however, Trump, a Republican, signed a tax bill reducing the penalty for not buying insurance to zero. The states challenging the law argued that the mandate was no longer a tax, and was therefore unconstitutional.

O’Connor agreed, and found that the rest of the law could not be separated from the mandate, meaning it must be struck down entirely.

About 11.8 million consumers nationwide enrolled in 2018 Obamacare exchange plans, according to the U.S. government’s Centers for Medicare and Medicaid Services.