The House has been telling Ryan to get behind Trump. That means their constituents are saying to them to tell Ryan to stand down.
Trump doesn’t need Ryan. Ryan needs Trump.
To date there has been a paltry size of Trump endorsements coming from within the house and Senate. Trump needs the voters that didn’t vote Trump. Some align to Ryan, some align to Cruz, Kasich, Rubio etc. Bring them in and work with them but drive your agenda. But they do have to work together