I think latest abandonment of Trump by the GOPe is related to the upcoming shut down fight. The GOPe doesn’t want to go the mat to fund the wall. It’s that simple. So they’re trying to weaken his position ahead of that battle.
The #1 priority of the GOPe has always been to protect to 30 year bipartisan policy of non-enforcement of laws and borders and the 30 million people they invited here against the will of the citizens.