My major beef with Trump and Republicans is that they DONT defend their principles and actions very well at all.
This, exactly this, is my primary objection to Trump. I think the reason he is so bad at defending his principles is because, in reality, he has none. He parrots right wing talk show gossip, because you "dance with the one that brung ya", but they aren't genuine convictions for him, and he doesn't even understand them. When called upon to defend conservative principles he makes a complete ass out of himself, as well as dragging conservative principles down with him.