Congress is in a political stalemate. At the moment, it is likely that the House led by Democrats will vote to impeach President Donald Trump Donald John TrumpBiden says voters should choose who nominates Supreme Court justice Trump, Biden will not shake hands at first debate due to COVID-19 Pelosi: Trump Supreme Court pick 'threatens' Affordable Care Act MORE, and that the Senate led by Republicans will not remove him from office. Some critical witnesses, including Gordon Sondland, Marie Yovanovitch, and others, have delivered revealing public testimony that implicated Trump in directing the White House quid pro quo scheme with Ukraine.

But John Bolton John BoltonJudge appears skeptical of Bolton's defense of publishing book without White House approval Maximum pressure is keeping US troops in Iraq and Syria Woodward book trails Bolton, Mary Trump in first-week sales MORE remains a significant missing piece to the impeachment puzzle. There is a great deal of uncertainty surrounding what the former national security adviser knows, whether he will testify before Congress, and what he would even say if he is compelled to do so. It is clear that Bolton could be a pivotal witness. According to a letter that his attorney sent to lawmakers, he was “personally involved in many of the events” at the center of the impeachment inquiry and in “many relevant meetings and conversations” that have not yet been covered in public testimony.

It is also apparent, with the decision last week by District Judge Ketanji Brown Jackson which ordered former White House counsel McGahn to comply with a subpoena to testify before Congress, that testimony from Bolton is more likely. While what he might say is difficult to predict, he has expressed a degree of animus and even insinuated that he has potentially damaging information about Trump that is not public. Bolton also teased that the White House was holding his personal Twitter account hostage since his resignation over fear of what he might say about this issue.

ADVERTISEMENT

The current evidence suggests that Bolton, whose departure from the White House was prompted by his proposal of a “Libyan Model” for North Korea, seems resentful of the president, given the rocky terms of his dismissal. Trump declared that Bolton “made a mistake as soon as he mentioned” the proposal then called it a disaster. It is impossible to say what the circumstances were and what information Bolton holds on the quid pro quo and terms under which aid to Ukraine was withheld.

However, given that Bolton is generally respected within conservative Republican circles, having served under President Bush, any testimony from him that directly implicates Trump in a bribery scheme would make it more difficult for Republican lawmakers to dismiss the inquiry as partisan. Similarly, any testimony from Bolton could all but vindicate the president. This explains why House Democrats have been reluctant to pursue him.

To be sure, it is still possible that a higher federal court could overrule the decision ordering McGahn to testify, which would of course have direct implications on whether Bolton will be compelled to testify under that same ruling. But as we saw during the impeachment of President Nixon, there is a longstanding bias that people who have information can and should be compelled to testify, notwithstanding executive privilege.

Given the closeness that Bolton had with Trump in his role at the White House, along with many of the occurrences surrounding the inquiry, it is clear that Americans deserve to hear Bolton testify before any articles of impeachment are considered rather than after. We should now ultimately expect that Bolton will be able to publicly offer his direct personal insights into what happened. However, what he will say, how he will say it, and what kind of portrait he will paint of the president all remain to be seen.

Douglas Schoen (@DouglasESchoen) is adviser to President Bill Clinton and former New York City Mayor Michael Bloomberg. He is the author of “Collapse: A World in Crisis and the Urgency of American Leadership.”