IF there is no wall then Trump will lose support. Which will not be his fault but that is how the game works.
I disagree. Trump voters aren't low information voters. They understand "how the game works". President Trump isn't the legislature. He isn't the Swamp.
If the Swamp prevents the wall from being built, the voters won't like it, but they sure as Hell aren't going to stay home—or vote Democrat—on that basis...