CHARLES LIPSON: The Political Logic of the Trump Trial.

Democrats may end up paying a higher political price than they anticipate. The trial won’t only delay Mr. Biden’s program. It will tarnish his image as a “unifier” eager to work across party lines. That identity will be much harder to sustain after Democratic senators vote in lockstep to convict Mr. Trump and push through a mammoth Covid relief bill without any Republican votes.

With all or almost all Democrats supporting Mr. Trump’s conviction, the president will be pressed to declare his position. Whether Mr. Biden speaks out or not, he signaled his position when he refused to dissuade Mrs. Pelosi from transmitting the House’s article of impeachment to the Senate. The speaker wouldn’t have done so over the new president’s opposition.

As the trial unfolds, Mr. Biden and Vice President Kamala Harris (who has begged off from presiding over the trial) will try to keep a low profile while avoiding any criticism of this party-line effort to denounce and convict Mr. Trump. That tacit approval will be universally applauded by Democrats and their media allies. But it leaves Mr. Biden facing backward, avenging grievances from the Trump years, not forward, advancing his own program. Partisan revenge is hard to reconcile with bipartisan restoration.

Presuming Democrats were ever interested in such a thing, of course.