When Reagan did it, many of us were unhappy. The tradeoff at the time was more border security & enforcement of rules. They forgot that part. This time, we don't want to give them a chance to forget.
Remember, the gov't estimates 11 million illegals. That means 20-30 million. Give them amnesty & they then have the opportunity to step to the front of the line, bypassing tens of thousands who are doing it legally from the outset. Once they apply for & recievve some speacial dispensation, they can then bring their spouse, children, aunts, uncles, grandparents, parents, blah blah blah-di-da-blah. So 25,000,000 now looks like 125,000,000 & that doesn't count the next wave of illegals looking for special dispensation.