All that is required to deal with the immigrant problem, is to make the consequences of coming here illegally so severe that the word gets out in the rest of the world: Don't do it.
All that is required to stop vote fraud is to make the consequences of doing it so severe that... Etc...
The problem is, we're too squeamish to throw the miscreants in jail and leave them there. We're too squeamish to round up the Mexicans and put them in camps in the desert on a lizards-and-water diet until either somebody comes to claim them or they die of old age. We're too squeamish to lock up for 20 years some bright promising young Demonrat college stoont who just "Made A Mistake" and voted twice, and ruin his/her/its life permanently in order to set an example.
Everybody watches TV and gets all maudlin and sappy over the poor 14-year-old pregnant Mexican girl who "just came here for a better life", and over the college stoont's wailing and crying mommy who wants her baby back, and the result is that the Gummint wants all of us ordinary stiffs to carry ID.
Your papers, Tovarich!!!