This nation has embarked on a grave process for only the fourth time in its history — impeachment of a president.

It’s a serious matter that should be treated as such by all concerned. It’s also a wrenching procedure that produces upheaval and can fan partisan flames. And, it must be said, it’s a necessary and entirely constitutional means of holding leaders accountable for misdeeds. It is no “coup” or sham, as Republicans have alleged, and they do harm to the institutions of this country and the Constitution they revere to tear down a basic means for holding presidential power in check.

The allegations against President Donald Trump are serious. It’s impossible to believe that if a Democratic president stood accused of attempting to bully a foreign country into investigating his political rival, with a desperately needed aid package hanging in the balance, Republicans would not feel obliged to act.

There is no sense in urging that this be a nonpartisan process. It is such by its very nature. But Republicans would do well to approach this inquiry with an open mind, to weigh their desire to protect a president of their party against their obligation to act as a check and balance on presidential power and uphold the Constitution.

The first week of testimony already has shown the need for public hearings. Americans heard powerful testimony from top diplomats William Taylor and George Kent. Both men have unblemished records of service. Both were appointed by this administration. Both have stepped forward, at great risk, to attest that Trump’s personal lawyer, Rudy Giuliani, was running a rogue operation in Ukraine, attempting to arrange the investigation Trump wanted of his political rival.

On Friday, Americans watched witness intimidation unfold in real time as Trump went after former Ambassador to Ukraine Marie Yovanovitch on Twitter while she was testifying. Yovanovitch has served the U.S. at some of the most difficult diplomatic posts in the world, from Mogadishu to Moscow to Kiev.

She was known within the national security community for her commitment to rooting out corruption in Ukraine. Her thanks was to have Giuliani launch a smear campaign against her, and have Trump call her “bad news” in his now infamous call to Ukraine President Volodymyr Zelensky, noting ominously that Yovanovitch was “going to go through some things.”

As much as anything, impeachment inquiries briefly lift the curtain on the inner workings of national politics, allowing average Americans to see and judge how politics is being conducted. That can produce important moments. One such moment came when, in a particularly chilling statement, Yovanovitch attested that “our Ukraine policy has been thrown into disarray, and shady interests the world over have learned how little it takes to remove an American ambassador who does not give them what they want.”

No U.S. president has ever been removed from office by impeachment. Two presidents were impeached by the House but acquitted in the Senate. One, Richard Nixon, resigned before the House voted on impeachment charges. The odds are against Trump being convicted by a GOP-dominated Senate.

And yet, this inquiry should go forward. Our nation risks lasting damage to its institutions, its security and its ability to act as a stabilizing force in a tumultuous world if it is unwilling to get to the bottom of possible serious misdeeds by its leaders. As difficult as the proceedings are to follow, we urge Americans to do so, because as citizens and voters, they provide the ultimate check and balance. To fulfill that duty, they need both parties to do their level best to vet allegations, witnesses and events. They need a media that upholds its responsibility to provide accurate, comprehensive accounts that illuminate rather than inflame or entertain.

It’s time to follow the facts — wherever they lead.