Is this before he’s reelected or after?-)
Given that the deep state did exactly this same play the first time he was elected, I would not be surprised in the least if this (thus far notional) DOJ "investigation" drags out through the next election as an "insurance policy" in case Trump or any republican who would be even remotely Trumplike in nature were somehow elected. Closing down this now (again, thus far notional) witch hunt investigation would be characterized in the media as a major scandal that shakes the very concept of justice to the core and the establishment would use it as an excuse to torpedo any of that future administration's actions. I can totally see that happening because that's already the lengths they went through in 2016 and they don't care that hundreds of people have spent months in jail on trespassing charges as political prisoners. To them, those people are not people.