I think you're looking back with rose colored glasses. I was an adult in 1986, and well remember the push for amnesty as being very much a big deal. The left put tremendous pressure on Reagan to sign it, all the while promising;
"This will be the first and last amnesty, and we'll build a border fence to stop future illegal immigration, if you'll just sign it."
Naturally, they were lying through their teeth. I felt so at the time, and Reagan should have too. Why he trusted those bastards, I'll never know.
On the other hand, the Soviets had been THE issue since we were little. Their evil imperialist socialism was death to everyone. It's why you had Thatcher, Reagan, the Pope, and others spending most of their time trying to fight them.
This took a huge amount of effort, and will. The rats, the media, the entire left made excuses for these evil people. Reagan took them out.
He also redid tax rates at the same time. Another biggie.
I still think you are blaming the wrong person, and that in 20/20 hindsight.