Don't just zero in on immigration or what can pass now. What is the vision? Why should people vote for the establishment GOP position? What even is the establishment GOP position anymore? The working paper you linked had "build the wall" as like the first position, that is literally the Trump position. What is their plan to advance that?
I am not an idiot and am a realist on things that sometimes can or cannot be done, so I don't need an explanation as to why legislating is hard when you can't just ram things through, but the Democrats seem to be moving legislation with slim majorities. They got their budget wish list last month because McConnell capitulated. They can do these things because they have a vision they are articulating. I don't like their vision and want it stopped but you also have to offer an alternative. The GOP establishment has not and is not providing an alternative version. We aren't even at the point of getting support for legislation on healthcare, the economy, the debt, immigration, trade, etc. because we don't have an alternative or vision being expressed.