The GOP Senators had no choice, if the agree with the military aid offerings, because there is not going to be any Senate bill on the border, because the Dims will never participate in a Border bill that the GOP should accept. The military aid bills and any border bills should be standalone bills, not conjoined. We did it in the House with an aid to Israel bill. The only reason that bill didn’t pass was procedural - how the bill got to the floor vote - which required a 2/3 majority to pass.
Why, somebody have a gun pointed at their heads?