What Drives GOP Nominee Donald Trump?

At the Republican National Convention in Cleveland Thursday night, party nominee Donald Trump will cap off this giant, four-day party with what is perhaps the biggest speech of his campaign.

He's said he'll "probably" use a teleprompter for the speech, something he's mocked other politicians for doing in the past, but his off-the-cuff, bombastic and often polarizing speeches are part of what has won him so many supporters.

That bombastic behavior is nothing new for Mr. Trump. In fact, even when he was a boy, he would throw birthday cake at parties or erasers at teachers — that's from reporting by Matt Viser, who covers national politics for The Boston Globe.

Matt Viser, national political reporter for The Boston Globe. He tweets @mviser.