If they make it to US soil it would be cheaper to fly them home immediately then to keep re-deporting them right across the border every couple of days. And fly them to the farthest airport that their country has.
If the law was followed, the wouldn’t
need to be re-deported.
“For the first improper entry offense, the person can be fined (as a criminal or civil penalty), or imprisoned for up to six months, or both. This is considered a misdemeanor under federal law (18 U.S.C.A. § 3559).
For a subsequent offense, or a reentry (or attempted reentry) after exclusion or deportation, the person can be fined or imprisoned for up to two years, or both. (See 8 U.S.C. Section 1325, 1326, I.N.A. Section 275, 276.) This is considered a low-level felony under federal law (18 U.S.C.A. § 3559).”