From 3 Nephi 16 (bear with me, it is a little long, but pretty interesting in this context):
6 And blessed are the Gentiles, because of their belief in me, in and of the Holy Ghost, which witnesses unto them of me and of the Father.
7 Behold, because of their belief in me, saith the Father, and because of the unbelief of you, O house of Israel, in the latter day shall the truth come unto the Gentiles, that the fulness of these things shall be made known unto them.
8 But wo, saith the Father, unto the unbelieving of the Gentiles--for notwithstanding they have come forth upon the face of this land, and have scattered my people who are of the house of Israel; and my people who are of the house of Israel have been cast out from among them, and have been trodden under feet by them;
9 And because of the mercies of the Father unto the Gentiles, and also the judgments of the Father upon my people who are of the house of Israel, verily, verily, I say unto you, that after all this, and I have caused my people who are of the house of Israel to be smitten, and to be afflicted, and to be slain, and to be cast out from among them, and to become hated by them, and to become a hiss and a byword among them--
10 And thus commandeth the Father that I should say unto you: At that day when the Gentiles shall sin against my gospel, and shall reject the fulness of my gospel, and shall be lifted up in the pride of their hearts above all nations, and above all the people of the whole earth, and shall be filled with all manner of lyings, and of deceits, and of mischiefs, and all manner of hypocrisy, and murders, and priestcrafts, and whoredoms, and of secret abominations; and if they shall do all those things, and shall reject the fulness of my gospel, behold, saith the Father, I will bring the fulness of my gospel from among them.
11 And then will I remember my covenant which I have made unto my people, O house of Israel, and I will bring my gospel unto them.
12 And I will show unto thee, O house of Israel, that the Gentiles shall not have power over you; but I will remember my covenant unto you, O house of Israel, and ye shall come unto the knowledge of the fulness of my gospel.
13 But if the Gentiles will repent and return unto me, saith the Father, behold they shall be numbered among my people, O house of Israel.
14 And I will not suffer my people, who are of the house of Israel, to go through among them, and tread them down, saith the Father.
15 But if they will not turn unto me, and hearken unto my voice, I will suffer them, yea, I will suffer my people, O house of Israel, that they shall go through among them, and shall tread them down, and they shall be as salt that hath lost its savor, which is thenceforth good for nothing but to be cast out, and to be trodden under foot of my people, O house of Israel.
16 Verily, verily, I say unto you, thus hath the Father commanded me--that I should give unto this people this land for their inheritance.
17 And then the words of the prophet Isaiah shall be fulfilled, which say:
18 Thy watchmen shall lift up the voice; with the voice together shall they sing, for they shall see eye to eye when the Lord shall bring again Zion.
19 Break forth into joy, sing together, ye waste places of Jerusalem; for the Lord hath comforted his people, he hath redeemed Jerusalem.
20 The Lord hath made bare his holy arm in the eyes of all the nations; and all the ends of the earth shall see the salvation of God.
Long story short, our gentile nation should be a lot more worried about our own righteousness than about who is crossing our borders, because the former will determine whether the latter poses any threat to us. Our safety lies in being counted as the Lord's people by doing as He would do.
And a last tangential thought: What better place than America to meld Jew and gentile into one as God's people? Surely here perhaps more than anywhere else, the seed of Abraham is spread among other ethnicities, so that those of natural lineage and those adopted in become indistinguishable, where the last can become first and the first last. I understand so little about how the prophecies regarding our day will play out, but what I do recognize fills me with awe and fascination. I hope to do my little part on the Lord's side, regardless of my inability to choose a political side.