> 1984.
I think it was 1986, as in the Immigration Reform and Control Act of 1986. [1]
> That way build sympathy for the law-breakers, then legitimize them via immigration reforms that only benefit the illegals
it was noted "The legalization provisions in this act will go far to improve the lives of a class of individuals who now must hide in the shadows, without access to many of the benefits of a free and open society. Very soon many of these men and women will be able to step into the sunlight and, ultimately, if they choose, they may become Americans"