One can't keep pushing the "anti-Establishment" thing and expect that people aren't going to notice that one is Establishment oneself.
Establishment isn't simply the opposite of conservative. It refers to insider connections.
If you went to Princeton and Harvard Law, worked in corporate law, politics, and government, and have ties to investment banking, like Ted Cruz (or if you spent years in Washington think-tanks or journalism, like Rich Lowry), it's best to not to try to play the anti-elitist card.
But Trump, who went to expensive private schools, went to Wharton, got his start with a few million from his dad, has ties to big business, big banking, national political figures from both parties, media connections, is worth a few billion, does business with Soros and Buffet, etc - HE can play the "anti-elitist" card?