I don’t think it’s fair to automatically characterize Trump supporters as racists. There is more nuance than that. The voters need to weight a candidate character, philosophy, leadership, policy position in balance. It also need to be weighted against its opponents, the other primary contenders and ultimately Hillary Clinton.
Republicans electorate has concluded with all his flaws, Trump represents the best of what the party has to offer. Most elected Republican officers concur and have endorsed Trump. To me, this is inexplicable. I don’t think any reasonable analysis will show that Trump is the better candidate compare to his primary opponents or Hillary. Republican party of now is not a normal political party. It stands for nothing but winning the election.