Something to consider here is that Mueller's indictments to date all involve people and criminal accusations that would be considered part and parcel of "The Swamp" by any objective measure. And by this I mean specifically the illicit foreign lobbying activities of various Swamp denizens like Paul Manafort, Michael Flynn and anyone else who is potentially named in a sealed indictment.
If this is the extent of Mueller's work, then it would be hypocritical for any Trump supporter to suggest there's something underhanded about the whole thing.
It's not, obviously. He's digging through the Trump family financial records, and per the report I linked above, even now digging through records at the RNC. The goal is to impeach Trump. If that fails, gather as much opposition research as possible to take him down in the next election. All paid for with tax dollars.