So can foreigners, so what’s your point?
It says “and” not “or”.
If they can’t be, they are not under jurisdiction. Like someone who is a diplomat cannot be arrested and tried in the United States, because they are not under jurisdiction.
But if they CAN be tried and arrested, then they ARE under jurisdiction.
That’s what jurisdiction means.
“So can foreigners, so what’s your point?”
Foreigners who are within the borders of the U.S. can be brought before a Federal judge, can compel witnesses for their defense, have benefit of the Grand Jury if charged with a capital or infamous offense, are protected against unreasonable searches and seizures, etc, etc.
If that’s not being subject to the jurisdiction of the United States (and re Supreme Court has ruled repeatedly that it is), words have no meaning.