Ed Morrissey

This seems like a very long shot; federal judges rarely accept a selective-prosecution argument. It does happen, however, and did recently in a federal case involving a fight between conservative protesters and Antifa goons, when the DoJ charged the former for a violent clash started by the latter.

This may not be quite as cut-and-dried, but it's close. The difference between this and the Biden case is that Biden cooperated with the searches. But that difference can be addressed in the obstruction charge, which could conceivably stand on its own -- and has always been Trump's biggest legitimate liability. 

Worth noting: Cannon has already denied Trump's motion to dismiss on grounds of "unconstitutional vagueness."