The filibuster, not any candidate, is what Republican voters are rejecting across the country There is no question that President Donald Trump is the most powerful person in the Republican Party, but it is equally clear that he was not the reason for four-term Texas Sen. John Cornyn, R-Texas, getting trounced in his primary Tuesday night. That was all the voters.When Trump endorsed Texas Attorney General Ken Paxton over Cornyn late last week, the die was already cast. The president, not surprisingly, just wanted his name associated with the win, and that is something that Senate Majority Leader John Thune,...