Only an ignorant open-borders nut would deny they are illegal.
Nobody denies they are "fellow human beings". That does not give them the right to demand entry into US or to sneak across the border.
And a rich nation should give them some soup and a blanket.
They don't want soup and a blanket. They want, no demand, to be let in.
A desperately poor nation might have the right to harm them.
Unless they engage in violence against border guards they should not be harmed (regardless of richness of the nation). At the same time, they should not be let in either.