Agree and disagree with this. I do think that if Trump wins, we'll see the Democrats change their tune on immigration. I think they'd be foolish to not do so.
But if Trump wins, it won't be because of the "open border" (there is no 'open border, and the Biden/Harris administration has not only seen a decrease in illegal border crossings since the end of Trump's administration, but have invested much more significant amotunts of money in beefing up border security technology than did the Trump admin). If Trump wins, it will be because enough Americans decided that they like or want authoritarianism. It really is as simple as that. I don't even think most Republicans (or the Trump campaign itself, for that matter) are denying that part anymore, that Trump seeks to be an authoritarian. They've embraced it, to their ignominious credit. So, if Trump wins, it will be because enough of our fellow countrymen decided that they'd rather have big government authoritarianism than big government liberalism.