It is painful to imagine a full four years of Donald Trump as president of the United States. He has created chaos, divided us, coarsened our public discourse, stigmatized the most vulnerable among us, surrounded himself with people who are manifestly unfit for public service, appointed cabinet members who are hostile to the very departments they have been selected to lead, and lied his head off.

But none of this is going to cost him his job, at least not until the next election. The only way we are going to free ourselves of Trump, without having to endure four more years of his presidency, is to impeach him.

The grounds for impeachment are set out in eight words in the Constitution: “Treason, Bribery, or other High Crimes and Misdemeanors.” Despite the elegant simplicity of those eight words, entire books have been written about their meaning. The meaning of “high crimes and misdemeanors” has been subjected to a dazzling variety of interpretations. The Woody Allen movie of that name, alas, didn’t clear it up. But it was a good movie anyway.

Only two presidents in our history have been successfully impeached by the House of Representatives, Andrew Johnson and Bill Clinton, and both remained in office after they were acquitted by the Senate. Richard Nixon got out of Dodge before the House voted on the Articles of Impeachment recommended by the Judiciary Committee.

Trump’s support from Congressional Republicans is a mile wide and an inch deep. If they turn on him, they can and will impeach him.

So far, Trump may not have done anything, at least not anything we know about, that rises to the level of impeachment. But don’t underestimate him. He can do it!

Four paths to impeachment look promising to me. You may have your own favorites, but here are mine:

The Russia Connection

We know for certain that Russia interfered with the 2016 presidential election to facilitate the election of Donald Trump. Some of their actions were clearly criminal. Hacking the DNC, for instance, was a crime.

We also know that during his campaign, Trump publicly encouraged Russia to hack the DNC, and expressed delight when the stolen emails were made public. This alone is probably not enough to implicate Trump in a crime, but it is close. If the various congressional and law enforcement investigations surrounding the Russian theft of the DNC emails turn up evidence that Trump, or surrogates acting under his instructions, secretly colluded with the Russians on this, it would not be a stretch to deem this a “high crime or misdemeanor.”

The Russian connection could also implicate Trump in criminal activity if it turns out that, prior to assuming the presidency, he instructed Michael Flynn to interfere with the Obama administration’s imposition of sanctions on the Russians in retaliation for their interference with the election.

This would be, on its face, a violation of the ancient, much-maligned Logan Act. The Logan Act makes it a felony for any citizen “without authority of the United States,” from carrying on “any correspondence or intercourse” with any foreign government with the intent to “influence the measures or conduct” of that government in relation to “any disputes or controversies with the United States, or to defeat the measures of the United States.”

Sputnik Photo Agency / Reuters

That’s a mouthful, but it’s not impossible to get through it. Flynn was certainly a “citizen” acting “without authority of the United States” when he had his pre-inauguration talks with the Russian ambassador. The talks were certainly a form of “correspondence or intercourse.” If Flynn was telling the Russians not to worry too much about the Obama sanctions, and not to overreact because incoming President Trump would make it all better, then he was clearly attempting to “influence the conduct” of Russia in relation to a “dispute or controversy” with the United States.

Critics of the Logan Act correctly point out that criminal charges have been brought under it only once in our history, in 1803. But it was amended by Congress as recently as 1994, so it is hardly a lifeless, ancient relic. And remember, we’re not talking here about a criminal case for violation of the Logan Act. We’re talking about an impeachment proceeding.

There’s a difference. In the Clinton impeachment, for instance, the Articles of Impeachment approved by the House of Representatives didn’t even cite specific criminal statutes. Rather, the Articles cited Clinton’s alleged crimes (as well as other conduct that arguably broke no criminal laws) only as “predicate acts” to the charge that he had violated his constitutional oath and duties as president.

Enough law school. The bottom line is that if it turns out that Trump was (1) complicit in Russia’s interference in the election, or (2) an active participant in Flynn’s arguably criminal communications with the Russians, there’s enough for a motivated Congress to write a credible Article of Impeachment.

And don’t forget the wild card in the Russia connection, the notorious “dossier” compiled by Christopher Steele, a retired British intelligence officer. The dossier, which dominated the news a month ago, contained shocking but unsubstantiated allegations that Russia had taken steps to compromise Trump by blackmailing him with sex tapes, bribery, and complicity in Russia’s stealing and leaking of emails and other documents.

The author of the dossier has now gone to ground, and the story has gone into hibernation for lack of corroboration. But as the lawyers say, “the absence of evidence is not evidence of absence.” Meaning that merely because something has not been proved by evidence doesn’t mean it isn’t true.

This story is still out there. It may be dormant, but it’s not dead.

If even a fraction of the allegations in the Russia dossier prove to be true, Trump will have the impeachment hounds barking at his door.

Refusal to Obey a Court Order

Trump’s contempt for the Judiciary has been on full display in his reaction to court rulings on his travel ban:

He has questioned the very legitimacy of the judiciary by calling federal judges with lifetime tenure under the Constitution “so-called” judges.

The lawyers representing him in court have denied the authority of federal courts to review his executive orders for constitutionality, something a unanimous three-judge Court of Appeals branded as “contrary to the fundamental structure of our constitutional democracy.”

He sent out his baby advisor Stephen Miller to proclaim, with alarming fascist undertones, that “the whole world will soon see” that Donald Trump’s actions “will not be questioned.”

Trump hasn’t personally defied or been caught instructing others to defy any court orders. Yet. But it doesn’t take much imagination to suspect that, one of these days, maybe soon, he will. Especially with the toxic boy-wonder Miller pouring poison in his ear.

Disobeying a court order could ignite a war between the Executive and the Judiciary, a full-blown constitutional crisis. That would most likely trigger impeachment proceedings.

Corrupt Business Entanglements

Although Trump has disavowed active management of his business interests, he has not divested them. That means he still owns them, and still stands to profit from their success.

Trump and his apologists make the nonsensical argument that a president “can’t have conflicts of interest.” Rubbish. Of course a president can have conflicts of interest.

What they are really trying to say is that the president, even if he has blatant conflicts of interest, is nevertheless exempted from a single federal statute that prohibits executive branch employees from participating in matters in which they have a financial interest. Well, bully for him.

Being exempted from one federal statute doesn’t mean the president is exempted from all laws implicating conflicts of interest. Hopefully the quaint Nixonian concept that “If the president does it, it’s not illegal” has been laughed out of serious consideration.

Being exempted from one federal statute doesn’t mean the president is exempted from all laws implicating conflicts of interest.

Laws that a president is not exempted from include bribery and the Emoluments clause of the United States Constitution.

Bribery is pretty much self-explanatory. A bribe is money or some other favor given or promised to influence the judgment or conduct of a person in a position of trust. Say, a president.

A president has enormous power to make decisions that can profoundly impact businesses all over the world. If the president also owns businesses all over the world, and stands to profit from their success, he has the power to shape policy in ways that lines his own pockets. If he does that pursuant to an understanding, even a tacit one, that he will exchange a policy favor for a financial advantage – in other words, a quid pro quo – he is accepting a bribe.

It is not easy to prove a quid pro quo, but it is not impossible. Judicial decisions, civil and criminal, are made every day by determining a person’s intent. Evidence of intent to engage in a quid pro quo might include a sudden change in a long-held policy decision which happens to be financially rewarding to the person who makes the change. Since Trump doesn’t seem to have any long-held positions, this could be particularly difficult in his case. But there are other ways to get there, and again, don’t underestimate him.

The Emoluments Clause of the United States Constitution is a different animal. That somewhat arcane constitutional provision has been animated, after centuries of slumber, by Donald Trump himself. Its rebirth is one of Trump’s many gifts to our public discourse.

The Emoluments Clause says that no person holding office (including the office of president) can accept “any present, Emolument, Office, or Title, of any kind whatever, from any King, Prince, or foreign State.”

OK, for those of you who prefer plain English, it means that the president can’t accept gifts from foreign powers.

The Emoluments Clause is narrower than the bribery laws and, at the same time, it is easier to prove. It is narrower because it applies only to gifts from foreign powers, not from private individuals or domestic sources. It is easier to prove because it doesn’t require a quid pro quo.

The relevant provisions of the Clause were designed to insulate American ambassadors from being corrupted by gifts from their foreign hosts. It prohibits receiving anything of value from a foreign power. It does not require that anything be given in return.

It is unclear whether Trump has violated the Emoluments Clause, but the potential is certainly there. A federal lawsuit has already been filed claiming that it is a violation of the Clause when a Trump-owned hotel rents out space to a foreign embassy, among other things. That may sound like small potatoes, but with all of Trump’s holdings, other instances will arise.

Gary Cameron / Reuters

And it is interesting to note that one of the major obstacles to any lawsuit claiming violation of the Emoluments Clause, the ability of a private plaintiff to convince the court that it has “standing” to assert the claim, vanishes in an impeachment proceeding. Certainly Congress, the branch of our government charged by the Constitution with the responsibility for policing unlawful conduct by a president, has standing to assert a breach of the Constitution by a president.

Of course, much more would be known about Trump’s financial dealings and entanglements if we could see his tax returns. Trump is not going to release them voluntarily, but disclosure could be compelled by Congress, or they could be leaked by somebody who already has them.

Perjury and Other Forms of Lying

If Donald Trump does anything consistently well, it’s lying. But if lying to the American people could get a president impeached, he’d be gone already.

Perjury, however, will get the job done. The trick will be to get Trump to lie under oath. The way to do that is simply to get him under oath. He’ll do the rest.

To be sure, it won’t be easy to get Trump under oath. That would likely require him to testify as a witness or a defendant in a lawsuit. Or to testify under oath before a Congressional committee. While there are lots of ways a president can dodge testifying under oath, sometimes it can’t be avoided. Ask Bill Clinton.

Keep in mind, though, that committing perjury under oath is not the only way to commit a crime by lying. Fraud, for instance, is a form of lying that can trigger criminal proceedings in the absence of an oath. So is lying to Congress. So is lying to the FBI. So is encouraging a witness to give false testimony.

President Clinton’s impeachment, for instance, was based not only on the allegation that he perjured himself to the Ken Starr grand jury and in the Paula Jones civil case, but also that he encouraged witnesses to give false testimony, gave job assistance to a potential witness, and “corruptly allowed” his attorney to make false statements during a deposition.

Given Trump’s penchant for lying, it’s not hard to imagine that this could be a path to impeachment. And the subject matter of his lies is bound to be far more serious than the subject matter of Clinton’s alleged lies.

Nobody can predict what might end Trump’s presidency. If he becomes malignant enough, the American body politic will reject him. Congress will follow suit if members come to believe that Trump is infecting them too.

Trump’s support from Congressional Republicans is a mile wide and an inch deep. If they turn on him, they can and will impeach him, even if the legal case is relatively weak. If they don’t, they won’t vote to impeach him even if the case is strong. That’s how it works.

At the end of the day, grounds for impeachment is pretty much whatever Congress says it is. If Congress wants to get there, the paths are open.

Philip Rotner is an attorney and an engaged citizen who has spent over 40 years practicing law. His views are his own and do not reflect the views of any organization with which he has been associated. Follow Philip on Twitter at @PhilipRotner