And he already has the support of Americans who support those goals. And those comprehensive goals to secure the border and reduce overall immigration is precisely what the Dims and their core supporters oppose so strongly.
In essence by making it a package POTUS is welding together a new constituency and robbing the DEMS of support in 2018 & 2020.
Not sure what your overall point is. The president might bring some new people into his constituency if he succeeds in implementing those immigration reforms, but he won't win over recent Third World immigrants or any of the hard core Dims.
It is a fantasy for some Republicans that recent poor and poorly educated Third World legal and illegal immigrants are going to become Republicans, not for any reason will it happen.
My point is that the conventional wisdom was that there were two fixed blocks, Dems & Repubs and they were not moving, to win you needed to motivate Indis.
In 2016 Donald Trump broke the mold and got significant support from a segment of Dems. He is continuing to fracture the Dem base support which produces a new group of more flexible votes ??Indis. The DACA folks can’t vote for years. I believe they will be by that time a much smaller group because a large% will not meet the criteria. The DACA supporters however are already voting. The wedge will accomplish two things: (a) by fracturing the base there will be a movement towards the fringes like La Raza which will make the Dem candidates that emerge less and less electable by the general electorate, (b) some of the disillusioned may begin to see that their aims better align with POTUS especially since they may have better wages, better job prospects and have received bonuses.
It is a many pronged attack, the best kind, where you keep adding weight to the scales and eventually the balance shifts.