“I think if Thomas Jefferson were looking down, the author of the Bill of Rights, on what’s being proposed here, he’d agree with it. He would agree that the First Amendment cannot be absolute.” - Chuck Schumer (D). Yet, Madison and Mason wrote the Bill of Rights, according to Sheila Jackson Lee, 400 years ago. Yup, it's a fact.
How will they manage that, since they have to stand in US territory? All the child has to do is walk across the (very shallow) river and into the arms of those guardsmen...which they've been doing this whole time with Border Patrol. They aren't seeking to get into the country and then do something. Surrendering to the Border Patrol is their object. How will this stop them?
You imagine that a bunch of armed national guardsmen will scare people from crossing, but if they can't shoot anyone (and they can't), then they just look big, dumb, and stupidly ineffectual. Way to go Rick Perry!