It's just gong to happen to you, because life isn't fair.
If you want to stop the migration we're going to see in the coming decades, it won't be war, but wholesale slaughter. Frankly, that conflicts too strongly with our view of ourselves as good people.
Besides, war with whom? Tens of millions of people fleeing their homes? Are you going to go to war with migrants, or maybe you think bombing their homes a bit more will make them less likely to leave?
If you're American, your original comment was referring to the US immigration policy? That would make that original comment seriously misguided.
As to the basic point however that you can somehow vote someone into power who's going to change the reality of how the world is turning out... ha. Ha ha. Unless you're voting for someone who's literally talking about shooting people at the border and letting them drown at sea, you're falling for someone's lies because you desperately want to believe them.
Then I'd ask why you're so desperate to believe them.