At the root of all these debates is the demographics of voters. There is a reason why a democratic candidate often wants as many absentee ballots removed as possible. Remove the military and businessman abroad, which is overwhelmingly Republican. Likewise, this issue not only is a hot topic for the Latino voter, it’s also something where the more they can register and get to vote the better, since these voters tend to be on the side of a more liberal candidate.
If I had to guess, this issue is purely about election demographics. Example: Years past (growing up overseas myself) in Germany a party called the SPD pushed very hard to have Turks and other minority groups in Germany be given voting rights. Guess what these people predominantly voted for?
That simple-
Immigration, Political Realignment, and the Demise of Republican Political Prospects