They have the leverage anyway...because they can deliver their rank and file as votes. The problem is far more fundamental than the stuff you are getting excited about - the separate issues here and there.
The fundamental problem is that Republicans cannot govern because they refuse to unify. They can never create a majority for anything except what the corporatist donors pay them to do. If you are going to fret over particular issues, you’d better first fret over the inability of Republicans to form a governing majority in Congress.
Don’t blame Trump for dealing with those who know how to make the process work and can deliver the votes to do it. Blame your factions in Republican Party that make it impossible for them to be a governing majority.