We tried amnesty back in 1986, and in 20/20 hindsight, it didn't work. It didn't work because people like Ted Kennedy gutted the employer sanctions short term, while subsequent administrations didn't enforce the sanctions and didn't properly fund the Border Patrol agency, in the long term. If Bush41, Clinton and Bush43 had enforced the employer sanctions and funded the PB properly, we wouldn't have the overwhelming problems we have with illegal immigration today.
It didn't work, because it didn't address the problem. Amnesty is a way of cleaning up the mess we created by not enforcing our immigration laws in the first place.
Amnesty will never stop illegal immigration, but it can resolve the problem of what to do with the 12 million illegal aliens already here.
There are two different problems that must be dealt with: 1) stopping illegal immigration, 2) dealing with 12 million illegal aliens. I don't really care how the second problem is dealt with as long as the first problem is dealt with.