The problem with polemics is that it mobilizes the opponents to bigger turnouts and more strident resistance. This was clearly a factor in the last national election, since DJT's endorsed candidates were nearly shut out in swing-states. 

Another axiom of politics is that self-described "moderate" voters dislike negativity and ideologues. Getting mired in the weeds of pissing contests on Twitter sticks in the craw of many non-aligned and undecided voters.