As the incoming head of the federal government, Donald Trump's words matter.
When a president-elect advocates two blatantly illegal punishments for Americans engaged in free speech, as Trump did Tuesday morning, it is significant. Trump's unusual statement has an immediate impact on civic norms and the political climate, regardless of whether one views it as a ploy for attention or a deliberate step towards illegally cracking down on free speech.
"Nobody should be allowed to burn the American flag," Trump wrote on Twitter, "if they do, there must be consequences - perhaps loss of citizenship or year in jail!"
There are no criminal consequences for flag burning, however, because the Supreme Court has twice ruled that flag burning is a type of political expression. That means it is protected from government punishment by the First Amendment, regardless of what Congress or the president thinks.
Legal experts say it's not a close call.
"This is protected speech," said Columbia law professor David Pozen. "The Supreme Court struck down flag burning laws."
While Trump's remarks did not cite any actual acts of flag burning, the topic was a major legal and political controversy in the late 1980s. The issue came before the Court twice, in fact, because Congress and state legislatures separately tried to ban flag burning.
Pozen, a former clerk to Supreme Court Justice John Paul Stevens and Judge Merrick Garland, emphasized the flag cases are settled law.
"It's very hard to imagine the Court overturning them now," he tells NBC News.
While it is flatly unconstitutional to jail a citizen for burning the flag, Trump's suggestion of stripping citizenship in response is even more extreme.
Asked if such a punishment has been contemplated for acts of political dissent, constitutional law professor Frederick Lawrence told NBC News, "First time I've ever heard of it."
"It's disturbing to suggest we should punish speech we disagree with," said Lawrence, a visiting professor at Yale Law School, adding that it is especially concerning coming from "the ultimate head of the federal government."
It is unconstitutional to strip citizenship for most crimes, and the Supreme Court has overruled attempts to do so for more grave matters than flag burning.
In a broad 1958 ruling, the Supreme Court held that the government could not revoke citizenship as punishment for desertion.
"The deprivation of citizenship is not a weapon that the Government may use to express its displeasure at a citizen's conduct, however reprehensible that conduct may be," wrote Chief Justice Earl Warren.
The case struck down such an effort as a violation of the Constitution's ban on cruel and unusual punishment, noting the repressive instinct to strip citizenship is a "form of punishment more primitive than torture."
The only way an American citizen can lose citizenship, under federal law, is by taking explicit action to "voluntarily" show intent of "relinquishing" citizenship.
Examples include formally declaring allegiance to another state, renouncing citizenship before a U.S. consular officer while abroad, or taking violent action to overthrow or "levy war against" the United States.
While Trump's proposed responses to flag burning are legally extreme, public criticism and condemnation for flag burning has long been widespread and bipartisan.
In 2006, 65 senators voted for a constitutional amendment to ban flag burning. That effort, which failed to reach the supermajority required for amending the Constitution, did not mention jail time or revoking citizenship as a punishment. The measure was backed by most Republicans and a third of the Democratic caucus, while prominent Democrats like Barack Obama, Joe Biden, Hillary Clinton and Chuck Schumer opposed it.
As an alternative, Clinton proposed legislation to ban flag burning designed to "promote violence." The symbolic legislation was legally redundant, since incitement is already a crime, regardless of the presence of a flag.
Burt Neuborne, a civil liberties lawyer who defended flag burning in several prominent cases, said that while the right to burn the flag is now a nonpartisan legal "consensus," it remains ineffective in the court of public opinion.
"It is not an effective way to protest," he told NBC News. "It outrages more people than it engages, and ends up being counterproductive, but it is legally protected."
On Tuesday afternoon, Senate Majority Leader Mitch McConnell, R-Kentucky, said he agreed with the high court on the issue.
"The Supreme Court has held that that activity is a protected First Amendment right, a form of unpleasant speech," said McConnell. "And in this country we have a long tradition of respecting unpleasant speech. I happen to support the Supreme Court decision on that matter."
Meanwhile, Sen. Joe Manchin, D-West Virginia, told NBC News Tuesday evening that "I would hope I could restrain myself but I'd probably want to beat the crap out of 'em," if he saw someone burning a flag.
Manchin said he supports the First Amendment, and wouldn't say that he would like to make burning the flag illegal, but said if someone wants to the burn the flag in West Virginia they should instead "just leave."
"If you don't like us, if you're that upset with the flag that represents the greatest country in the world, leave," Manchin said, "Just leave. Don't burn the flag just leave."