" about the Clinton campaign doing so"
Selective outrage.
News flash: campaigns do oppo research on their opponents.
The only reason that they would not would be 
1) limited resources
2) if the lessons in name calling that you learned in 3rd grade are sufficient
3) you have a foreign dictator doing it for you, hand delivered by a kremlin attorney to a meeting of your campaign surrogates
4) you have a foreign and hostile intelligence service (Wikileaks labeled as such by Pompeo) down it for you
5) you have your biggest campaign donor supporting the same hostile foreign intelligence service