Illegals are a fact of life so if reducing their number is a positive thing for the US the bill should have been passed. Alas it was a negative for Trump so he killed it. You should be very proud. BTW, there were no 'poison pills' in the bill that I'm aware of.The devil is in the details. That bill allows illegal immigration, just reduces the number allowed per day.
Also,, a Bill will often have rider Bills attached, so frequently it is those attached Bills that cause a "host" Bill to be voted against.