Reality check. What good is it going to do to withhold money? The invasion is already here. Withholding money isn't going to affect those already here. Threatening to withhold money is futile. Standing his ground and saying that we will NOT allow any migrants into this country would be effective along with arming the border and making it very clear, that ANYONE caught crossing over our border will be considered an enemy of this country and shot. It will take one fatality, maybe two, before the message becomes clear.
I know it may seem cruel and heartless, but think of those American citizens who have become victims at the hands of illegals.