This allows them to deny reality for any matter of science whether it's global climate, abortion, education, gun control, economics and any other issue which requires science to produce evidence in order to select the proper course of action.
It all these cases and more the scientific facts are diametrically opposite to the direction of Republican and conservative legislation.
By making science the stuff of the devil it leaves a gigantic opening for them to stuff their nonsense into the heads of the gullible right wing base.
But as far as Trump himself goes, he's not really a Republican. He is solely concerned with receiving praise and feeling tough. There is no master plan; that is really all there is to it.
Yes, he is. He may not have a particular devotion to an ideology you'd like to pretend defines the Republican Party, but the US electoral system structurally produces duopoly between parties too broad to have coherent ideology.
To put another way, if you averaged out the beliefs of all who consider themselves Republicans, Trump himself doesn't believe most of it, certainly not dogmatically.
I think dragonwriter's point is that this is also true of most (many?) other Republicans.