According to a really interesting perspective by Richard L. Hasen in an article published in Slate, Trump’s senate impeachment defense will be to put Joe Biden on trial. Hasen concludes that:

A trial of Biden or CrowdStrike in the Senate could be a Trump victory, or it could be a morass for Senate Republicans. Remember that the whole point of pressuring Ukraine was not to get the government there to actually do an investigation but only to announce an investigation. The goal was not to get at the truth but to open up a line of attack on the man Trump saw as his most dangerous rival. Trump was banking on the premise that it could be enough to sully someone’s reputation repeatedly through public attacks rather than to have to produce actual evidence to harden public opinion. Days of Senate hearings in which Trump lawyers lay out a case against Joe Biden or CrowdStrike will presumably get wall-to-wall coverage from major news outlets, further amplifying Trump’s lies against Biden and efforts to blame Ukraine and rehabilitate Russia for the 2016 election interference campaign.

Now some moderate senators like Maine’s Susan Collins may balk at such a defense, but they really have very little control here. Just like a criminal defendant, Trump gets wide latitude to launch his defense. It seems unlikely that the chief justice would shut down an attempt by Trump to present evidence supposedly going to his state of mind in pressuring Ukraine. Trump’s state of mind is crucial in determining whether he abused his power and acted corruptly.

It’s already clear that Trump will try to use the Senate trial to his political advantage. The strategy is a gamble, but it could pay off. Conviction takes a two-thirds vote, which would mean near three dozen Republican senators joining the Democrats to convict, an outcome that would not be possible if the vote were held today. In the likely event that Trump is acquitted after sullying Biden, the president will take a victory lap and perhaps turn to new ways to curry foreign interference in the upcoming 2020 elections. It will still ultimately be up to American voters to determine if they will side with those presenting evidence of the president’s abuse or with those peddling Trump’s false conspiracy theories.