Every ruling party of every country on Earth already does that.

'I don't like who they let in' is an entirely different criticism from 'They let anyone in!'

It's dishonest to pretend that the latter is happening.

Not a rightwing idea.

However, violence, intimidation and human rights violations during immigration and customs enforcement in order to pump hateful and jingoistic populist support is a rightwing idea. The steelman for it is that it “intimidates” would-be immigrants, but the counterargument is that it’s senseless strongman violence enacted on desperate people[1] running from terrible situations that ironically the US have had a direct hand in manufacturing.

This is quite common to far-right rhetoric:

  - You agree that we should [very mild and centrist idea, commonplace across the world]
  - Good, now that you agree then you should have no opposition to [human atrocities]

Edit: [1] and once you’ve built your apparatus for violence against migrants, and you’ve successfully dissuaded the migrants who are marginally less desperate, you’re now committing heinous crimes against the most desperate migrants, in a vicious feedback loop of unimaginable suffering. Like forcing a woman and her child who were fleeing sex trafficking into a camp under fluorescent lights where the woman will be raped, her child taken away from her, and both ending up with substandard care for infectious diseases that they catch.

That's neither a left nor right position. Many extreme capitalists, a right wing ideology, support open borders. Meanwhile China, North Korea, Cuba, Vietnam etc do not seem to have open borders / liberal migration policies