By Noah Feldman / Bloomberg Opinion

The extended trial brief filed by Donald Trump’s lawyers advances three defenses: that Trump did not incite the Jan. 6 attack on the Capitol; that the Senate can’t try a president who is no longer in office; and that the First Amendment protects Trump from being impeached for words that, they say, don’t meet the requirements for criminal incitement conviction laid down by the Supreme Court.

The factual defense is highly unconvincing, as anyone who watched Trump’s speech on Jan. 6 and saw the attack can attest.

The argument that the Senate lacks jurisdiction over a president who is out of office is disproven by history and Senate precedent.

The free speech argument is also wrong in a basic sense: The First Amendment prohibits Congress from making any law abridging freedom of speech. But this doesn’t apply in impeachments any more than the Sixth Amendment right to a jury trial would apply to the Senate impeachment trial.

Yet the First Amendment defense requires deeper engagement than the other two, if only because it is less absurd. If it did apply to impeachments, the Supreme Court’s incitement jurisprudence contained in the famous 1969 case of Brandenburg v. Ohio probably would have protected Trump’s speech.

The major component of Trump’s argument is that the First Amendment applies to elected officials. As the lawyers put it only a little ungrammatically, “the fatal flaw of the House’s arguments is that it seeks to meet out governmental punishments — impeachments — based on political speech that falls squarely within broad protections of the First Amendment.”

To support their argument, Trump’s lawyers cite Wood v. Georgia and Bond v. Floyd. Both are important Supreme Court cases, but neither proves that the First Amendment should apply to impeachment.

The 1962 Wood case arose when a local Georgia judge impaneled a grand jury and charged it to investigate supposedly suspicious block voting by African-American citizens. (Think of it as a precursor to today’s false allegations of election scams, but in the context of the civil rights movement.)

While the grand jury was sitting, the local sheriff denounced the whole charade, telling the press that “Whatever the Judges’ intention, the action … will be considered one of the most deplorable examples of race agitation to come out of Middle Georgia in recent years … . This action appears either as a crude attempt at judicial intimidation of negro voters and leaders or, at best, as agitation for a ‘negro vote’ issue in local politics.” The judge responded by holding the sheriff in contempt of court.

In an opinion by Chief Justice Earl Warren (not Justice William Brennan, as Trump’s lawyers say), the court held that the contempt order violated the sheriff’s free speech rights. The statement hadn’t interfered with the sheriff’s performance of his duties, the court explained, and added, “The role that elected officials play in our society makes it all the more imperative that they be allowed freely to express themselves on matters of current public importance.”

This decision was about a judicial act — the contempt order — that would have imprisoned the sheriff. It had nothing to do with impeachment. It certainly shows that public officials possess First Amendment rights. Trump does, too. But that means only that he can’t be criminally prosecuted for protected speech, not that he can’t be impeached for inciting the Capitol attack.

The Bond case, in 1966, involved an attempt by the Georgia legislature to refuse to seat the civil rights activist Julian Bond when he was elected to that body. The legislature claimed that, because Bond opposed the Vietnam War and the draft, he could not have sincerely taken his oath to support the Constitution and laws of the United States. In another opinion by Chief Justice Warren (also misidentified by Trump’s lawyers as Justice Brennan), the court explained that free speech applies not only to “the citizen-critic” but also to an elected legislator.

The ruling that the Georgia legislature could not keep Bond from taking office does not suggest that the First Amendment prohibits impeachment for Trump’s incitement. The Georgia legislature wasn’t impeaching Bond. It was making up a reason to exclude him from serving in the first place; conduct outside the bounds of its authority.

Apart from the moral outrageousness of comparing Donald Trump to Julian Bond, the citation seems meant to create a supposedly “liberal” argument for applying the First Amendment to Trump. (Maybe that’s also why Trump’s lawyers wanted to invoke Justice Brennan, even though he didn’t write either of the opinions.)

That effort is unavailing, or should be. A robust commitment to free speech doesn’t require protecting from impeachment a president who uses words in an attempt to destroy the democratic process.

Had Trump’s lawyers been more forthright, they might have argued that, although the letter of the Constitution allows Trump to be impeached, the Senate should apply the spirit of the First Amendment to the case, and therefore take into account the Brandenburg definition of incitement. That argument would at least have been constitutionally respectable.

Even then, the House managers would have a good answer: that Trump violated the spirit of the Brandenburg rule by encouraging the attack on the Capitol. The former president probably couldn’t be punished criminally for what he said on Jan. 6. But for the high crime of trying to break democracy, he can and should be barred from running for office again.

Noah Feldman is a Bloomberg Opinion columnist and host of the podcast “Deep Background.” He is a professor of law at Harvard University and was a clerk to U.S. Supreme Court Justice David Souter. His books include “The Three Lives of James Madison: Genius, Partisan, President.”