Impeachment has jumped the shark. The episode that proves it is the one in which serious, informed politicians are wondering if Donald Trump actually wants to be impeached for political advantage and is trying to goad Democrats into obliging him.

It would be impossible to imagine a more preposterous scenario under the Constitution and in the history of the presidency. Impeachment was intended by the constitutional framers as a highly serious option reserved for only the most extraordinary, egregious violations of the rule of law. Today’s discussion treats impeachment as a trivialised gambit within the ordinary game of electoral politics. The undermining of the constitutional ideal is near-total. It’s almost laughable.

To be clear, impeachment itself is and has long been a matter of high seriousness. Not so long ago, Richard Nixon resigned from the presidency to avoid the historic disgrace of being impeached. Bill Clinton toughed it out, famously. But neither he nor anyone else doubted that his impeachment, however motivated by partisanship, became a permanent stain on his personal and presidential legacy.

Whether you think that Clinton was guilty of high crimes and misdemeanours or not, it mattered enormously that he was just the second president in 200 years to be impeached. The House Republicans pushing his impeachment were not just saying that they wanted to make it harder for Clinton’s vice-president, Al Gore, to win the next election; they were making the argument that Clinton was a genuine criminal who had subverted the justice system by lying under oath.

Fast forward 20 years. When critics of the Trump presidency started discussing impeachment almost as soon as he took office, they meant to do much more than achieve some political advantage. Or at least I did. In my role as a constitutional law professor, I wrote several essays trying to make sense of the law, history and theory of impeachment. I went back and read books on the subject going back to the 1970s.

I wasn’t alone. Two of my most distinguished colleagues at Harvard Law, Laurence Tribe and Cass Sunstein, each wrote full-length books on the ins and outs of impeachment. Both had worked for Barack Obama. Yet both went to great lengths to avoid saying that Trump deserved to be impeached on the basis of available evidence. Instead, they provided nuanced analysis of constitutional precedent and logic. The point of the exercise was to help guide the public in a rational, non-partisan way through the thickets of possible constitutional crisis.

Of course, no scholar or expert would deny that there is a political aspect to impeachment. Some politics is inherent in a constitutional structure that places impeachment responsibility in the House of Representatives and the trial to remove a president in the Senate. The framers may have been idealistic, but they weren’t naïve. They knew that elected politicians would not be free of political motivation. Nevertheless, they also made successful impeachment and removal very difficult, precisely to discourage Congress from taking the whole process lightly. They chose words with grand implications — “high crimes” — to underscore that removing the president outside of elections must not be undertaken lightly.

Yet somehow, all the talk in the past 2½ years has robbed impeachment of its original serious content and atmosphere. Maybe it is just too many rapid-fire conversations on CNN, MSNBC and Fox News, with their constant drumbeat of partisan prediction and preoccupation. We have talked about impeachment in the partisan context so much that we can no longer imagine it as something more than an electoral ploy.

The blame for this development goes to both parties. Since the 2018 midterm election, House Democrats have made it painfully clear that discussing impeachment is primarily or even exclusively a tool to weaken Trump’s chances in 2020. You almost never hear a Democrat say: “We have a moral duty to impeach even if it will cost us the election in 2020.”

Rather, the idea of impeachment and the idea of electoral advantage have become inextricably entwined.

On the Republican side, there has been much gleeful speculation that a Democratic effort to impeach Trump would bring out the Republican base in huge numbers. Trump himself is clearly toying with the possibility that this may be true — hence his recent efforts that seem to be daring the Democrats into action, or at least making them look like wimps if they don’t impeach him.

That leaves us with the preposterous notion that the President could or would somehow bring about his own impeachment to help him get re-elected. Gone is the traditional notion that impeachment itself would be a blot on Trump’s reputation. Not that Trump has ever cared much about reputation in the ordinary sense, but he very clearly wants to be remembered as a great president. In his mind, however, being impeached apparently wouldn’t stand in the way of his lionisation as a leader.

Trump’s beliefs about politics and the Constitution are nothing if not a reflection of this instant in time. That he is treating impeachment as mere rhetoric shows that impeachment has lost its sting. That’s sad enough for now. It will be much, much sadder in the future, the next time we need impeachment to mean something.

• Noah Feldman is a Bloomberg Opinion columnist. He is a professor of law at Harvard University and was a clerk to US Supreme Court Justice David Souter. His books include The Three Lives of James Madison: Genius, Partisan, President