Trump is not an ideologue. In some contexts, that is a good thing. However, Trump is not an ideologue because he has no core convictions, no principles that guide his thinking or decisions. He really doesn't know very much and he doesn't appear to believe anything.  His world revolves around Donald J. Trump.  Everything he says and does is driven by what he perceives, in the moment, to be in the best interest of Donald J. Trump.