President Trump threw his support behind a new effort to ban burning the American flag on Saturday, challenging a decades-old Supreme Court ruling that established flag burning was a protected form of speech.

"All in for Senator Steve Daines as he proposes an Amendment for a strong BAN on burning our American Flag. A no brainer!" Trump tweeted Saturday morning.

Sen. Steve Daines (R-Mont.) and Rep. Steve Womack (R-Ark.) reintroduced companion legislation in the Senate and House on Friday, which was Flag Day, to restore "Congress's constitutional authority to ban the desecration of the United States flag."

Forty-eight states had laws against flag burning until the 1989 Texas v. Johnson Supreme Court decision ruled that the act was protected under the First Amendment's freedom of speech clause.

Trump has frequently cited the flag as a symbol of national pride, at times even embracing flags at rallies when he appears on stage.

He suggested after his election in 2016 that people who burn flags should have their citizenship revoked or serve jail time.

"Nobody should be allowed to burn the American flag - if they do, there must be consequences - perhaps loss of citizenship or year in jail!" he tweeted.

Politicians and previous presidential candidates from both parties have backed proposals to outlaw some forms of flag burning.

According to The New York Times, the Supreme Court is unlikely to reconsider the issue of flag burning anytime soon. Right-leaning Chief Justice John Roberts and conservative Justice Brett Kavanaugh have suggested they support the court's 1989 decision on the matter.