Projection

The Trump campaign is trying to make the case that Biden is an empty vessel that the progressive wing of the Democratic Party will use to get their agenda implemented. That's ironic coming from a Republican Party campaign that thought it could use Trump the as an empty vessel to promote its own agenda. And in a still more ironic twist, Trump ended up turning the tables on the GOP, using it to further his own selfish interests. Using one’s own failings as the framing of other's action is what psychologists term "projection".