The big problem here is that the basis for his reasoning, one of the first things he mentions, is that Hispanics have common ground with Republicans on social and economic issues but are driven away over the stance on immigration.
That simply isn’t true. The overwhelming issue that had Hispanics voting for Dems in 2012 was their support for ObamaCare. That IS a social/economic issue, one that represents a chasm between the GOP and Hispanics.
Moving positions on immigration won’t change that, but it will create more voters who are supportive of Dems on a whole host of other issues.