“You can commit treason in one of two ways,” Larson said. “One is you can levy war against the United States, which is essentially raising an internal rebellion to overthrow the government. Trump clearly didn’t do that.
"The other would be adhering to the enemy, giving them aid and comfort. And 'enemy' is defined very precisely as foreign nations or groups with whom we are in a state of open war, and we just are not in that state with Russia — indeed with most countries around the world we're not in a state of open war.”
Being an agent of a foreign government isn’t itself necessarily treason. It’s not good, of course, but you can be an agent of, say, France without committing treason for the simple reason that we’re not at war with France. (It’s also worth noting that the question at issue — if Trump was acting on Russia’s behest — is still outstanding. Mueller’s probe considered the question, but it wasn’t summarized in Attorney General William P. Barr’s letter released Sunday. The FBI is expected to brief Congress on the results of that investigation soon.)
Later Monday, Trump himself appeared to accuse his critics of themselves of committing treason.
"There are people out there that have done some very, very evil things, very bad things — I would say treasonous things — against our country,” Trump said in the Oval Office. “And hopefully the people that have done such harm to our country — we’ve gone through a period of really bad things happening — those people will certainly be looked at.”
Again, criticizing the president isn't treason.
“That’s completely ludicrous and, I think, extraordinarily inappropriate, given that one of the purposes of the treason clause” — Article III, Section 3 of the Constitution — “was to protect Americans discussing and criticizing their government,” Larson said. “It was very clear — one of the reasons to limit the offense the way it was done in Article III was to prevent it from being a political tool where people in power use it to suppress their political enemies.”
Trump’s suggestion that his opponents were committing treason in criticizing him is “absolutely contrary” to the intent of the Constitution, Larson added.
The government has, in the past, attempted to create a category of prohibited behavior that would make it easier to target criticism as illegal. A century ago, Congress passed the Sedition Act of 1918, amending the Espionage Act to tamp down criticism of the government during World War I. The law was used to, among other things, arrest Socialist leader Eugene Debs for criticizing the draft. He served more than two years in prison. The law was repealed after the war ended.
About a century earlier, John Adams signed into law the Alien and Sedition Acts, which barred the publishing of “false, scandalous and malicious writing” targeting the government. A number of newspaper editors who opposed the administration and the ruling Federalist Party were jailed. Eventually, the laws were mostly repealed or expired.
You probably noticed the “alien” part of the laws’ name. Adams also sought to limit immigration and make it easier to deport foreign-born individuals. Presidents signing into law legislation targeting immigrants, political opponents, the media and Socialists? Every century or so, it seems to become popular once again.
Trump and Sanders’s description of criticism as involving treason is inaccurate. Their targeting critics in stark terms, though, is not without precedent.