Why should they change? It's working. See what I just did here?
I'm strongly in favor of legal, controlled immigration. No little girl should have to be dragged to the border as a get out of jail free card. Life is suffering, and the mother who put her kid in that place was trying again to get here, because that's where she sees hope. I'm fine with letting that happen, but there's a process, and this doesn't cut it as a workaround. Everyone in a developed nation will have to build a strategy for the triage of the border control process. This is an issue that will get much worse before it will ever get better. Some feel that using this as a club to beat Trump and his supporters into shape is a good strategy.
It just gives the folks out on the edge of the right more gravitas when the righteous press looks at Trump supporters and those in the gray middle and tells them that they are moral cowards not to hate Trump like we do because look at this picture of suffering. This is then interpreted by the recipients as "they hate us and will grind us to dust when they take control." The cynical right rolls up the harvest, and you do their work.
Meanwhile: