Over the past year I have been a strong and consistent critic of Nancy Pelosi’s very cautious approach to the impeachment of Donald Trump. I continue to believe that it was foolish for House Democrats to focus so narrowly on the Ukraine matter, and equally foolish to rush forward to impeachment on the basis of that alone. More could have, and should have, been done to strengthen the case against the President. It might also have helped to build a strong political case looking toward the 2020 elections.

But what is done is done. And this past week the Democratic majority in the House voted to impeach Trump.. And then things took a strange, and perhaps not unexpected turn. McConnell and other Senate supporters of Trump very publicly expressed their disdain toward the impeachment; McConnell indicated that he was consulting with the White House, and not his Democratic Congressional colleagues, about the logistics of the Senate trial; and then McConnell indicated that he was planning to dispatch the entire matter as quickly as possible.

This surprised no one. But then Pelosi did the unexpected. She took up an idea first floated months ago by Harvard constitutional scholar Laurance Tribe, and indicated that she was not yet sure how and when she would actually deliver impeachment charges to the Senate, thus triggering an impeachment prosecution and a Senate trial; and she  suggested that she might well wait and make sure that McConnell would commit himself to a serious public trial in the Senate.

The consequence was well-described in a December 19 Roll Call headline: “Impeachment chicken: Pelosi, McConnell and the battle for leverage over a Senate trial.” In the days that followed, Pelosi has stood pat, while McConnell has expressed disdain for the very notion that Pelosi might have any leverage at all. As The Hill reported:

“It’s beyond me how the Speaker and Democratic leader in the Senate think withholding the articles of impeachment and not sending them over gives them leverage,” McConnell told reporters after criticizing the House impeachment effort in a lengthy floor speech. “Frankly, I’m not anxious to have the trial. If she thinks her case is so weak she doesn’t want to send it over, throw me into that briar patch,” he added.

In a technical sense McConnell is clearly right: if the House Democrats wish to prosecute Trump in the Senate, then at some point they must file the charges, which is under the control of McConnell.

But in a broader political sense things are less clear. McConnell may face two pressures that force him to adjust. One is Trump’s own apparent impatience for a public vindication, which can only occur, however imperfectly, through a trial. A second is the possibility that a handful of relatively “moderate” Senate Republicans—Mitt Romney, Susan Collins, and a few others—might refuse McConnell’s extreme partisanship, and be persuaded to join with Senate Democrats to create a majority in favor of a relatively fair trial (my colleague Jeffrey Tulis has joined with Never-Trump Republican Bill Kristol to promote this idea at The Bulwark).

Either of these factors could cause McConnell to compromise. Or not.

But there is another possible pressure, one completely in Pelosi’s hands: she can very publicly declare that if agreement on a fair Senate trial cannot be reached by a set date, then House Democrats will not transmit the existing two articles of impeachment, but will also reopen the House investigation of Trump’s misdeeds. House Democrats could then immediately re-issue subpoenas for the testimony of Mick Mulvaney, Mike Pompeo, William Barr, and others not yet called, perhaps including Mike Pence, Rudy Giuliani, or Trump himself.

Pelosi could then declare that she is doing this only because Senate Republicans have refused to take the impeachment seriously, and she can publicly call upon federal judges who would be called upon to rule on these subpoenas to expedite their rulings. While waiting, House Democrats could either call other witnesses, including the many Republicans or former Republicans, not in office, who support impeachment.

There are risks to doing these things. House Democrats are surely as exhausted by the impeachment process as the rest of us, and some of the more moderate among them are put at greater political risk the longer the process plays out. Furthermore, while re-opening the process could bring pressure on Republicans and could even lead to further damning revelations, it also could alienate many ordinary citizens who don’t understand, and perhaps resent, what is going on in the first place.

These risks are significant. But impeachment itself was a huge risk, and once House Democrats started down this road, they committed themselves, not only to the Constitution, but to a political contest against an unscrupulous opposition. It may just be that the only way to keep impeachment from being thrust into a Senatorial black hole is to make a bold gamble. Either the Senate organizes a fair impeachment trial and allows for important relevant witnesses to be called, or the House Democrats will call those witnesses themselves, presenting the testimony that the Senate refuses to allow, and that the public deserves.

Jeffrey C. Isaac is James H. Rudy Professor of Political Science at Indiana University, Bloomington.