There are many.
But after his RNC speech, there are a couple that jump immediately to attention:
• His use of "I" language. Most presidential candidates — even the most narcissistic — use "we" language, precisely to avoid charges of narcissism and incipient strongmanism. "I alone can fix it" suggests that there aren't any principles that can guide America toward solutions, only the application of Trumpian will. It's very cult-of-personality strongman type stuff. "I am your voice," too, sounds like a way of assuming the people's sovereignty into the Trumpian person.
This is scary stuff.
• Too, there's the assumption — the promise — that problems will bend themselves to the Trumpian will. There are no hard problems, no messy and sometimes contradicting ideals. Opposing forces will bow down before him, or be wiped out. Nothing is hard. On Jan. 20, 2017, he promises, the world will go, Wizard of Oz-like, from black-and-white to color, transformed instantly into a Trumpian wonderland of "law and order."
All politicians overpromise. This is something different. Wariness is recommended.