If Guliani were to call a special press conference to say that "This has gone too far and our country is now endangered," then lay out ambitious and believable and doable plans to reverse the tide of illegal immigration- complete the wall now! fine and jail employers of illegals now! etc., if he then insisted on this new revelation every time he speaks along with his other issues, he would have clear sailing through the election. I would not vote for him, even then, but I think he would win. It is THE issue in the country that has had no effective voice because the MSM opposis and gives it no air and the leaders, almost all of them in both parties, have been pro-illegal.
I say Giuliani because he is the one already in the MSM eye and is still the leading candidate. He would get the air time, the serious commentary, even if it is all rabidly negative.
If he were to do these things, the problem would begin to fix itself as the election gets closer and the issue gets loud and likely to be addressed, whoever is elected.