Congress has the power of the purse, and can fund or defund at will. As far as allowing unchecked migration goes, there is enough blame and pointy fingers for 3 lifetimes. Their other duty is to check power from the other 2 branches when needed, and that has been pretty lacking lately too, The only things the get done in Washington is when some unseen hand directs them to work together. You've seen this happen after 911 and the patriot act, which had already been written and sitting on someone's desk, was unanimously passed by all parties with no discussion. All of our recent military actions also happen with lockstep co operation, same with the the covid choreographed response. Money for Ukraine and Israel and adding to the debt proceeds with very little scrutiny except for the people being taxed to pay for it. This new social restructuring also seems to have the benefit of the prime mover. Illegal migration and enforcing the laws we have don't seem to be on this fast track for some reason, and what we have left is guessing who dropped the ball. The truth is the whole team doesn't want to score.