Well,for starters we could cite the emoluments clause which T-Rump has walked all over.  Then there is the First Amendment guarantee of freedom of religious exercise and the Fifth Amendment’s promise of equal protection of the laws which his ban on Muslims from certain countries entering the country thumbs his nose at.  Says BloombergNews, "...Trump’s utterances on Twitter or elsewhere could become evidence in court of what he intended to accomplish with the executive order. Some possible examples include his original call during the presidential campaign for a “total and complete shutdown of Muslims entering the United States” and his modified demand for a ban targeting immigrants from majority-Muslim countries."  I could go on but it is fruitless to argue with a brick.