1. Governments using trolls is different than campaigns hiring people to discuss politics. Campaigns get volunteers all the time to affect public discourse by going door to door, sending mailers, and doing all kinds of things.
2. Trolls specifically have an antisocial goal. The trolls employed by Russian military intelligence engaged in a psy-ops campaign against America to raise domestic tensions along racial and social lines. They specifically targeted races and ideologies and used aggressive, violence-promoting tactics. By contrast, Hillary hired Americans to talk about politics online.
3. It's not illegal for campaigns to hire citizens to promote their politics online. It is illegal for foreign governments to engage in military intelligence psy-ops campaigns against our citizens, and for campaigns to coordinate with those campaigns and request them.
I think the worst part about seeing you bring up "Correct the Record" is that they spent $9 million dollars in a $1.6 billion dollar campaign. https://www.opensecrets.org/pacs/lookup2.php?strID=C00578997...
The conspiracy theories and propaganda that were created about this program are some of the most ridiculous lies of the 2016 cycle, and I think really go to show how little research people are willing to do before they repeat propaganda. "Correct the Record" exposes a classic propaganda pipeline for the right, because it was a tiny program that did very little, but the right managed to turn it into a massive huge conspiracy where every pro-Hillary comment must be a troll. Which was a response, of course, to the validated and legitimate left criticism that pro-Trump actors were actually foreign psy-op campaigns. There needed to be a "Both-sides-ism" to excuse the fact that a foreign government conducted a military intelligence operation against our elections.
Even today this conspiracy boogeyman gets play all over the internet, a remnant of disinformation used to justify an attack on our elections.