David M. Perry is a journalist and historian. He is senior academic adviser, history department, University of Minnesota. Follow him on Twitter. The views expressed here are those of the author. View more opinion articles on CNN.

(CNN) "History will not be kind to Donald Trump," Adam Schiff soberly intoned in his closing statement Monday during the impeachment trial.

Schiff may be right about history, but history doesn't just happen. We're going to need the very information that Trump and the Republican Senators have declined to make public, not just about the impeachment, but countless other alleged misdeeds committed by this administration. If historians are going to do their job, we're going to need some help.

David M. Perry

Over the past few months, the Trump administration has done everything possible to obfuscate the facts of the misconduct with Ukraine. With the willing assistance of Republican Senators who refused to call witnesses , even those like John Bolton and Mick Mulvaney with first-hand knowledge of the President's conduct, and likewise refused to subpoena the documents that the Trump administration has been withholding, Republicans are clearly hoping to sweep the detritus of impeachment behind them.

And yet, the schisms that threaten to tear the United States apart grow ever more vast, and there's just no way to reverse that trajectory while so many alleged misdeeds of the Trump administration lie concealed in shadows. The work will only really be able to start when Trump is out of office, but if America is going to ever heal the deep partisan rifts in our body politic, we're going to need leaders committed to revealing the ugly truths of these last few years. The realities that get documented now are the ones that will shape that story later -- and both sides know it.