The big bump occurred, not due to 86 amnesty, but due to Clinton Treas Sec Rubin destroying the Mexican economy (for their own good) in the 90s. Rubin forced the Maquiladoras to flee Mexico for Asia. Those unemployed then looked for jobs where they could find them... here. When the fled there were no longer customers for the retail sector... So the retail employees...and business owners also came here.
I heard a second rationale: NAFTA allowed our farm products to go there very much cheaper and made their small backward family farms unviable. Thus the peasants looked for other stuff to do.
clinton’s nafta also destroyed mexican farmer who couldn’t compete with US grain producers.