If my boyfriend has been here for 20 years but keeps getting deported and now is going to be barred how can i get him back?

It is unlikely your boyfriend will be able to legally return to the U.S. Most drug convinctions make a person permanently ineligible for permanent resident in the U.S. There is a limited exception for possession of marijuana. In addition, youbindicayed your boyfriend has been deported on more than one occasion. This also triggers a permanent bar to admission. This bar cannot be waived until the person has been outside the U.S. for ten (sometimes twenty) years.