Donald Trump cleared up one thing in his speech in Charlotte, North Carolina, last night: he is running to win. Throughout this very odd election cycle, some pundits have periodically suggested that Trump wasn't serious in his run for the presidency. First, it was said that he got into the race simply to garner publicity, to burnish his "brand." He himself, it was said, was surprised that he did so well in the primaries. When it became clear that he was poised to win the nomination, the story changed slightly. Now, he was said to be playing the buffoon because...