I mean in general. I don't twitter, at least not much and with zero engagement.
That old saw about "remember that behind every user is a human with feelings" -with the IRA shenanigans we've seen that disproven time and time again. With Wikileaks. With Guccifer (sp?) ..who was a human being, sure; but he was a human being who was a high-ranking member of the russian government.
Even with someone who is very transparent, it's pretty common for conservatives to dig into the bag of dirty tricks (the gish gallop, moving goalposts, etc) when entering into a debate.
It's been proven that assuming good faith in an argument is dumb.
In any high-stakes, heavily trafficed arena (twitter, facebook, reddit,etc) I think it's good to remember there's a 90% chance you're dealing with someone who is coming from a place of bad faith and either deliberately, intentionally get down in the mud with them (PRS style

), or ignore them and in your responses play to the rational folks that might be reading.
Of course, like with every other thing that involves politics, there's another cliche that happens to be highly appropriate: