[cynwoody]

Robert Mueller has a long and sordid history of illicitly targeting innocent people that is a stain upon the legacy of American jurisprudence.

Try just:

Robert Mueller has a long and sordid history of illicitly targeting innocent people, a stain upon the legacy of American jurisprudence!

And follow with snark aimed at federal pigs such as Comey's counsel Robert Fitzgerald, whose life's achievement (putting away Scooter Libby) just got undone by POTUS, or Mueller's #1 goon Andrew Weissmann. Or Mueller himself.

[alexander_busek]

cynwoody: Robert Mueller has a long and sordid history of illicitly targeting innocent people [noun phrase 1], a stain upon the legacy of American jurisprudence [noun phrase 1]!

I don't like appositions. Let me therefore weigh in with my own modest proposal:

Robert Mueller's long and sordid history of illicitly targeting innocent people is a stain upon the legacy of American jurisprudence!

This is demonstrably the syntactically simplest, most-concise solution so far.

It has the added charm that it takes "his long and sordid history" as a given - i.e., it is implied, rather than claimed (and their more difficult to refute).

Regards,