That idea had nothing to do with Trump, he has never given a damn about any of that extreme religious fanaticism.  This comes from promises he offered to Pence when he offered him the VEEP when others refused to run with him.  Pence and his coalition crave to increase the power of a theocracy.  The US is acting like an Islamic theocracy or kow towing to another religion like the catholics banning abortions  in Ireland or in many latin american countries because of the power of the  bishops.
Pence would have us return to Puritan times when they could hang Quakers or Catholics and Maryland could jail protestants for not paying tithes to the Catholic churches.  We keep trying to separate church from state, but zealots still want to make sure everyone follows their rules in the long run.  They pretend moderation and tolerance until they get dominant power; Then EVERY religion demands control.
Congress will make NO law to establish religion; pro or con, support or oppose, belief or not.