Westboro Baptist’s protests have an ulterior motive if they are indeed a leftist front group.
Maybe they are designed to pave the way for a “gay” military by uniting vets and soldiers with gay activists-liberals who show up to protest Westboro.
Otherwise, Westboro is just a bunch of insane wackos.
I see them more as an anti-Christian front group as opposed to a leftist front group. Nearly everything they do goes against the teachings of Jesus, and most people who have even a cursory working knowledge of those teachings (sadly, that number is far too low) can see right through their tactics.
I believe the WBC's targets are not gays per se, but rather people who are considering Christianity, or people who identify as Christians but who are not particularly religious. Their preaching of these lies about Christ will have a terrible effect on people who know of Jesus, but who do not know Jesus. Their preaching also plays right into the hands of people who are opposed to Christianity. These activities give such people a free "Christians are haters" card to play against the faithful.