The NAFTA deal has hit a last-minute snag because one key provision in the House bill negotiated between the Democrats and Trump trade officials was not cleared with the Mexicans. This is the all-important provision giving U.S. inspectors the right to verify whether Mexico is carrying out its commitment to allow free trade unionism.

Jesús Seade, Mexico’s chief trade negotiator on NAFTA, objected that this measure was news to him, and violated Mexico’s sovereignty. Mexico’s Senate had approved the new agreement without the latest add-on language. They also didn’t bother to read the U.S. implementing bill before storming through to pass their version, determined to hit a deadline rather than carefully review the terms. Reading is fundamental.

The likelihood is that some gimmick will be found to paper over this hitch. (Unenforceable side agreements are what got us into the NAFTA morass in the first place.) Mexico needs this deal, and so does President Trump. Ironically, Trump, normally found demonizing all things Mexican, has emerged as an unlikely ally of Mexico’s left-wing president, Andrés Manuel López Obrador, who is personally committed to free trade unionism.

Trump’s NAFTA stance creates the illusion that he supports unions. Some even imagine that since NAFTA is nominally reciprocal, Mexico or Canada working with the U.S. labor movement could lodge complaints against union-busting in the U.S.

Don’t hold your breath. The add-on bill singles out Mexico for enforcement. No inspectors from Canada or Mexico can monitor practices in the U.S., though in principle complaints are allowed.

But Trump’s is the most anti-union Labor Department on record. His labor secretaries have systematically dismantled the Obama administration’s efforts to restore labor rights.

When it comes to trade unionism, the new NAFTA is mostly about optics and election-year posturing. If we want labor rights, that will take a new administration.