Donald Trump long ago turned the presidency into a mechanism for feeding his ego and stuffing his wallet. It has been observed that his presidency resembles that of a corrupt Third World regime, complete with nepotism and attacks on objective sources of information. Instead of Trump serving the people, government is converted into an operation designed to cater to his needs.

He taps foreign governments for emoluments and his own administration for hotel revenue; stages counterproductive summits to be the centre of attention and get despots’ praise; lurches from one counterproductive policy to another — especially on immigration and trade — to fire up his base and portray himself as a tough guy. He lies incessantly and compels his aides to do the same to avoid responsibility and prevent his low-information voters from figuring out he has no idea what he is doing.

Trump’s imperious, grudge-holding attitude — like his financial corruption — is wordlessly communicated to underlings. They come to understand and anticipate what his frail ego demands. When, for example, the administration is caught politicising the Navy, which confirmed it received a request from the White House to “minimise the visibility” of the USS John S McCain during Trump’s visit to Japan, his acting chief of staff, Mick Mulvaney, declares it was not an “unreasonable thing”.

Do not upset the king, the courtier tells us.

The self-enrichment and contempt for equal branches of government have now become de rigueur for his underlings. A slew of Cabinet and senior level officials — former Environmental Protection Agency director Scott Pruitt, former HHS secretary Tom Price, treasury secretary Steven Mnuchin, commerce secretary Wilbur Ross, counsellor to the president Kellyanne Conway — have been caught up in ethics scandals, including Hatch Act violations. When caught as a multiple Hatch Act offender, Conway contemptuously asks when her jail sentence begins, suggesting rules are for little people.

We do not know if Trump acts to advance his own emotional and/or financial needs or to advance the interests of the American people when he covers for Saudi Crown Prince Mohammed bin Salman’s involvement in the murder of columnist Jamal Khashoggi, when he takes Russian president Vladimir Putin’s word over the findings of the intelligence community, and when he excuses the brutal conduct of North Korea’s dictator, Kim Jong Un.

Lying and bullying have become epidemic — and not just by the President. Secretary of State Mike Pompeo misleads Congress — for example, on evidence tying MBS to Khashoggi’s murder, on progress in North Korea talks — and treats committee members dismissively. His attorney-general misleads the public and, like other department heads, refuses to respond to congressional subpoenas. When Homeland Security secretary, Kirstjen Nielsen lied about the existence of a child separation policy.

Trump’s fixation with climate-change denial becomes official US policy; his flatly wrong conception of tariffs becomes the de facto talking points for the administration. Trump’s exaggerations or outright false claims become the official line on the economy and the Federal Reserve Board. As cars run on petrol or electricity, Trump runs on lies. It is the fuel that enables him and his lackeys to operate.

It is in this context that equal branches, the military, the media and voters must assess his misconduct and determine whether it is essential to remove him from office before 2020. The mound of evidence just from the Mueller Report of obstruction of justice surpasses the evidence the House Judiciary Committee had on Richard Nixon when it voted on articles of impeachment. At this juncture, however, it is a near-certainty he would avoid removal by the Senate.

Impeachment is not, strictly speaking, punishment — for that, post-presidential state and federal prosecution awaits Trump. The purpose of impeachment is twofold: it is an act of constitutional hygiene — to expose attacks on American democracy and reaffirm constitutional principles — and it is an act of self-protection. What conduct would, if allowed to continue, do fundamental damage to the republic?

Walter Shaub, former head of the Office of Government Ethics, tells me: “We’ve already crossed the line of ignoring congressional subpoenas and fake declarations of emergency. We are now at the precipice of ignoring a court order.” He continues: “So what is the red line? Ignoring a court order, dispatching troops to the border and assigning them an active role, invocation of the Insurrection Act to send troops door-to-door looking for immigrants, interfering in the election, refusing to recognise the results of an election?”

He asks: “Which of these things would have to happen before people would be willing to say a red line has been crossed?”

Here is how the House may choose to proceed: begin hearings to gather and present facts relating to Trump’s possible crimes, ethical lapses and assaults on the Constitution. Call it Trumpgate hearings or whatever else suits the House’s fancy.

At the end of those hearings, which, like the Watergate hearings, will take months, public opinion could move — or not. (According to the latest CNN poll, support for impeachment rose from 37 per cent to 41 per cent in a month.) Trump may assist that process by crossing one of those red lines — “self-impeach”, as the House speaker put it.

Put former White House counsel Donald McGahn on the stand to see if support for impeachment gets to 50 per cent. Subpoena Robert Mueller to take us through the ten categories of conduct relating to obstruction of justice. Call forensic accountants to explain the foreign money that flows into Trump’s pockets.

Call former intelligence figures to explain why Trump’s invitations to Russia to meddle were a threat to national security. See if the Southern District of New York prosecutors advise us of the results of their investigations. According to Attorney-General William Barr, they can tell us if they think Trump could be indicted; they just cannot actually indict him.

Censure may result. Impeachment may be the outcome. Or maybe by that time, we are on the eve of election, and the voters decide his fate. What is clear is that in big ways and small, Trump has abused and misused his office. His conception of government — his alter-ego not unlike his eponymous real estate business — is antithetical to constitutional democracy. A light must be shone on that, it must be denounced and, ultimately, the Government must be rid of Trump and his enablers. Democracy depends on it.

• Jennifer Rubin writes reported opinion for The Washington Post