Someone already 110% correctly called it out, but the whole 14th Amendment thing is absolute bullshit propaganda, like with a lot of what these fuckers try to pull. It's amazing how they care so much about specific amendments when it suits them, but completely ignore a bunch of the big ones like 1A, 2A, 4A, 10A (they flipflop on this one big time though) and so on.

"Subject to the jurisdiction thereof" is huge, and cannot be applied to illegal invaders. The whole reason it was worded that was, as I recall, was to not provide birthright citizenship. This barred people like the American-born children of foreign diplomats from instantly becoming US citizens. The idea that the same amendment means if a pregnant illegal sneaks across the border and pops out a baby they're Americans is absurd on its face.

The 14th also talks about protecting the rights of specifically American citizens.

TL;DR: They're lying about the 14th Amendment. This is not shocking, and is par for the course.