Open borders means cheap labor for large corporations. Large corporations care only about profiting their shareholders. Large corporations regularly donate vast fortunes to political campaigns. The Senate used to be able to have closed session voting with anonymous polling methodology. Ever since this has been removed, politicians vote exactly how they are paid to vote every time they vote. The constituents don't matter when all they know about their political leaders is the garbage fed to them through a 9" screen sitting between their hands or the 5' TV in the living room.