Impeaching a president is an investigational endeavor that requires both a lens and a mirror.

It demands an examination of actions by the person to whom the country has entrusted the most powerful office in the world. But impeachment also means examining what we as a nation have decided to tolerate.

That is why it was fitting that House Intelligence Committee Chairman Adam B. Schiff (D-Calif.) opened Wednesday’s public impeachment hearing by reminding us of three shocking words that acting White House chief of staff Mick Mulvaney uttered last month.

Mulvaney publicly admitted that President Trump attempted to turn hundreds of millions of dollars in congressionally appropriated security aid for Ukraine into a lever to force that country’s president to take actions that would help Trump’s own political interests. And then Mulvaney said: “Get over it.”

“There’s going to be political influence in foreign policy,” Mulvaney added, though he later tried to backtrack from what he had offered in a startling moment of candor about how the Trump administration views this country’s national security interests.

Extortion, coercion, bribery — name it what you will. Schiff called it all of those things. But then the Intelligence Committee chairman posed the real questions at hand: “Is that what Americans should now expect from their president? If this is not impeachable conduct, what is?”

And what does it say about a country that could look at Trump’s actions and decide to shrug them off?

The basic facts have been pretty well established at this point, by the public servants who have come forward to corroborate them, but also by the president himself.

Trump keeps telling us to “read the transcript” — the official notes that were taken of a July 25 phone call in which he asked Ukrainian President Volodymyr Zelensky to “do us a favor.”

He wanted two favors, actually, both of which put Trump’s own political interests over those of this country.

First, Trump asked Zelensky to dig for evidence that would elevate a wacky conspiracy theory that undercuts the U.S. intelligence community’s conclusion that Russia interfered with the 2016 presidential election in hopes of influencing it in Trump’s favor. The second was a request that Zelensky open an investigation that could smear former vice president Joe Biden, who at the time appeared to be Trump’s most formidable potential Democratic opponent.

Republicans keep arguing that all of this is simply the latest iteration of what Rep. Devin Nunes (Calif.), the Intelligence Committee’s ranking Republican, called “a three-year-long operation by the Democrats, the corrupt media and partisan bureaucrats to overturn the results of the 2016 presidential election.”

But the sober and compelling testimony of William B. Taylor Jr., the acting ambassador to Ukraine, and George Kent, deputy assistant secretary at the State Department overseeing European and Eurasian affairs, turned out to be anything but the “theatrical performance” Nunes predicted it would be.

No doubt there remain pragmatic arguments to be made against the path upon which the House has now set itself.

If the House does indeed bring impeachment articles to the floor, they will likely pass with little or no Republican support. The subsequent trial in the Republican-controlled Senate appears virtually certain to end with Trump’s acquittal, which the president and his supporters would surely claim as an exoneration.

Then there is the awkward timing of this endeavor. If the goal is to remove Trump from the office whose powers he has so flagrantly abused, wouldn’t it be better to let the voters do that in an election that is now less than a year away? By deepening and inflaming partisan divisions, the Democrats might actually end up helping Trump get reelected.

But the more fundamental challenge here is the one that Trump himself has raised by his disregard for the oath he took to faithfully execute the duties of his office.

If the House were to ignore its own constitutionally mandated duty to hold him accountable, what constraints would there be on anything he chooses to do from here on out? Or for that matter, on what future presidents decide to do?

There is still a case to be made. That is what an impeachment investigation is designed to do. This nation’s founders built a system of government that operates on checks and balances. Trump has acted in ways that make a mockery of that principle. If the House were simply to look the other way and “get over it,” Congress would be guilty of doing the same.

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