ISIS attacks on Christians are religiously motivated. Belief in God has nothing to do with religion. No believer needs to identify with a group or its symbols, sharing the knowledge can be done in a living room or kitchen without creating a risk.
"Then there is the Democrats’ midterm deficit. Democrats generally have a more difficult time getting their voters to turn out for midterm elections. Many Democrats regularly vote in presidential races but stay home during midterms. The electorate in midterm years is generally older and sometimes, depending on the state, whiter than in presidential-election years. Animosity toward Obama and his policies also makes Republicans more eager to vote. All of that gives the GOP an advantage."