Although an editorial, it explains the lack of enforcement since "Reagan's Amnesty" back in 1986.
"In the years that followed, Washington showed little interest in the law's border-enforcement provisions — to the point where border security under the Obama administration became a bad joke.
And three decades after the Reagan-era reform, illegal immigration in the U.S. has quadrupled."
https://triblive.com/opinion/editor...son-on-immigration-enforcement-before-amnesty
Lax border enforcement and lack of employers of illegals being prosecuted under the stipulations required under the reform, we have the problem we have now.
Every presidential administration since has dropped the ball on illegal immigration, yet when Trump is trying to enforce existing laws, he is demoralized by the left.