This nifty little video explains some reasons why Donald Trump is crushing it in the Republican race. Short words, repetition, rearrange your sentences so you put the sharpest word at the end.
Donald Trump speaks at a Fourth Grade reading comprehension level. I bet an analysis of Bill Clinton's speaking style would show similar things. I've noticed that when Hillary talks, you have to think about what she said in order to parse it, while when Bill talks, you feel like you just totally got it. As Churchill said, "Short words are best. Short words when old are best of all."
(Don't like the guy or his politics, this is just a rhetorical analysis.)