(CNN) President-elect Donald Trump proposed on Tuesday a penalty -- including possible jail time or loss of citizenship -- for burning the American flag, in spite of two US Supreme Court rulings that protect the act under the First Amendment as a form of free speech.

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

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

The Supreme Court has twice affirmed the right to desecrate the American flag as a form of free speech -- a historically contentious issue -- in cases before the high court in 1989 and 1990.

The following year, in "United states v. Eichman, " the top court again affirmed the right to burn the flag when it ruled 5-4 that the Flag Protection Act of 1989 -- passed by Congress in response to the Johnson decision -- was unconstitutional.

It's not immediately clear what prompted Trump's tweet Tuesday morning, though the national discussion of respect for the flag has been restarted in part following a flag burning November 10 on the campus of Hampshire College in Amherst, Massachusetts, as part of a post-election protest. The university then decided to stop flying the American flag at the campus, which also infuriated some members of the community.

Steve Vladeck, CNN legal analyst and professor at the University of Texas Law School, said Trump's suggestion that citizens possibly be expatriated as a penalty is also a non-starter.

"In addition to ignoring the Supreme Court's clear teaching that flag burning is constitutionally protected speech, Mr. Trump's tweet also casually suggests that citizens should lose their citizenship as a 'penalty' for such acts," Vladeck said. "Even if flag burning wasn't protected, it would still be unconstitutional to deprive someone of their citizenship without some voluntary act on their part to renounce their allegiance to the United States or pledge fealty to a foreign sovereign."

When asked about the Supreme Court rulings on CNN's "New Day," Trump transition spokesman Jason Miller repeatedly dismissed questions about the constitutional protections of flag burning.

"Flag burning should be illegal," Miller told CNN's Chris Cuomo. "The President-elect is a very strong supporter of the First Amendment, but there's a big difference between that and burning the American flag."

But Trump's opposition to the protection of flag burning puts him at odds with conservative leaders like Senate Majority Leader Mitch McConnell and deceased Supreme Court Justice Antonin Scalia, whom Trump has praised as a "brilliant Supreme Court Justice, one of the best of all time."

Trump himself has tweeted about the importance of free speech, including a message he sent in 2013, quoting George Washington.

"'If the freedom of speech is taken away then dumb and silent we may be led, like sheep to the slaughter.' - George Washington,"

"If the freedom of speech is taken away then dumb and silent we may be led, like sheep to the slaughter." - George Washington — Donald J. Trump (@realDonaldTrump) February 15, 2013

In a 2012 interview with CNN , Justice Scalia defended the right to burn the flag, explaining the difference in his personal and judicial opinions on the subject.

"If I were king, I would not allow people to go around burning the American flag -- however, we have a First Amendment which says that the right of free speech shall not be abridged -- and it is addressed in particular to speech critical of the government," Scalia said.

"I mean that was the main kind of speech that tyrants would seek to suppress," he added. "Burning the flag is a form of expression -- speech doesn't just mean written words or oral words -- burning a flag is a symbol that expresses an idea. 'I hate the government, the government is unjust,' or whatever."

And McConnell wrote a 2006 op-ed for the Central Kentucky News titled "Flag stands for freedom, even to desecrate," in which he defended the right to burn the flag.

"No act of speech is so obnoxious that it merits tampering with our First Amendment. Our Constitution, and our country, is stronger than that," he wrote. "Ultimately, people like that pose little harm to our country. But tinkering with our First Amendment might."

Still, banning flag-burning has drawn mainstream support before. The Flag Protection Act of 1989 was supported at the time by President George H.W. Bush, before it was ruled unconstitutional, and the Flag Protection Act of 2005, another failed attempt to criminalize flag burning, was co-sponsored by then-Sen. Hillary Clinton.