I think he is not, and the evidence is his America First policies, and the actual things he has done and is doing that can only benefit America. Immigration is the first thing that comes to mind, although I won't be completely convinced until the southern border wall is up.
He brought the corporate tax rate way down, which means the overseas profits of American companies can be be withdrawn from international banks and brought to American ones, where they will be used to invest in America. He's also taking a very aggressive stand on trade agreements and on tariffs -- and you can argue how much this will actually benefit the States, but America does have some bad trade agreements and after all Trump's big talk, he will probably just renegotiate NAFTA with a slightly bigger percentage in favour of American companies.
He ran as an anti-globalist, which is the opposite of what the elite want, and the insane lengths to which they have gone to destroy him are probably the best argument that he is not one of them.
I don't believe that just because someone is a billionaire they are part of the elite. I don't believe that the elite are nearly as all-powerful as some people think. They are not this great, cohesive group that controls every dollar and piece of information on earth. If they were, things would be a lot different.
I have said before that I think Trump, good and bad, is the real deal. He is far too natural in the role of himself to be a puppet. I would be very surprised if he was a part of the elite, just as I would be very surprised if some of the members of his family were not.