“It’s not an American value to be told what to do by the federal government,” Cassidy said in a news conference on his bill in the Capitol.

Cassidy’s Patient Freedom Act is intended as a response to a potential U.S. Supreme Court ruling expected later this month that could gut the 2010 health law — better known as Obamacare — by disallowing the federal subsidies that help low- and middle-income residents buy insurance through the federal exchanges that operate in the three dozen states that did not set up their own ACA health-insurance exchanges. Lousiana is one of those states without its own exchange.

Cassidy, a Baton Rouge gastroenterologist, explained his proposal to a Washington nonprofit group last month, but did not file the legislation until Tuesday. If approved by Congress, it almost certainly would draw a veto from Demopcratic President Barack Obama, for whom the ACA is a signature legislative achievement.