Love him or hate him, there are some components to Trump running that candidates really need to embrace. 1st and formost....authenticity. He doesn't come across as a politician. He doesn't come across as reading off some talking point sheet, put together by a bunch of PC advisers. He's up front with what he believes, and doesn't flip flop to which way the political winds are blowing at any given moment. Much like Chris Christie.
Also....he doesn't care about sucking up to the "Establishment". I mean, the GOP won this MAJOR election last go around, campagining on issues that really mattered, repealing Obamacare, a referendum on nearly every policy and exectutive action Obama pushed, and after they resoundly defeated the Democrats via the people's decision on that referendum, turned right around and ran from every Democrat criticising them for daring to try and run on what they campaigned on. Trump would stick to what he campaigned on.
Just a couple of the issues that GOP candidates can take from the Don, that would go a long ways in improving their electoral chances