2016 Postmortem

When I say they are a coalition of single issue voters, I don't believe their is a single overriding issue that binds them together

the anti-LBGT crowd will vote for whoever will 'stop the gays'
the anti-choice crowd will vote for whoever is the most anti-abortion
the gun crowd will vote guns
the religious right will vote for whoever says Jesus the most
the greedy wealthy will vote for whoever promises the greatest tax cuts
the ag crowd will vote for farm subsidies
and yes, the bigots will vote for whoever they feel will be hardest on minorities

Based on what I see around me (A very red county in PA), there is not too much overlap between these categories. Most seem to fit in one category, two at most. They don't care about much else politically, but they will show up just about every election to vote their key issue. All the republicans have to do is be to be closer on that individual's one or two hot issues, and they get the vote.