He wouldn’t give them their wars, that’s probably the biggest thing. He wouldn’t prop up Obama’s Yemeni genocide, that was a sticking point at the time. Pulling a lot of their climate change grift policies also angered them. Dropping regulations and encouraging companies to manufacture here really pissed them off as well. It’s endless, you can’t have every facet of the establishment attacking him in every way imaginable and him being some darling of them like Obama.
Closing the borders also really pissed them off, big business depends on cheap illegal labour, and the establishment wants open borders for a number of other reasons.