They would just call him up ( and get through? ), set up a meeting at Trump Tower or Mar-A-Lago? REALLY?
Trump has known and donated to many pols, throughout his life; mostly for business reasons.
Friends in the Military? No; though he admires them and has always donated to certain charities for Vets.
How do you know he had no friends in the military? Additionally, if any in the military, currrent or retired, wanted to get in touch with him, they easily could. Trump was contact with veterans’ organizations for one thing.
Or, Trump having a stratospheric IQ, in mulling over his run, realized that the only institution not completely soaked through with Obama filth, would likely be the military, so he (being a billionaire) wangled an invitation or two to some event where military brass were at, and began his *own* networking.