The article from EL UNIVERSAL on this state boundary dispute told us that the
Mexican Constitution had been amended in December to provide that such disputes
would be settled by the Senate, rather than by the courts.

The text of the two-page constitutional amendment is found at
www.cddhcu.gob.mx/leyinfo/refcns/dof/CPEUM_ref_163_08dic05.pdf .

Here are the changes summarized and paraphrased in English by me:

Federative entities (states) can fix the boundaries between them by friendly
conventions, but such adjustments aren't effective until approved by the Senate.
If ageeement is lacking between states, whichever of them may put the case to
the Senate. Resolution by the Senate of such matters shall be definitive and
cannot be challenged. The Supreme Court will have jurisdiction over only the
execution of the Senate's decrees. Such decrees approving boundary changes by
friendly convention between states and those deciding controversies require the
vote of two-thirds of those present. During its next regular session following
the amendment, the Senate shall establish the Federative Entity Boundary
Commission (Comisión de Límites de las Entidades Federativas) and provide by law
for its make-up and functions. State boundaries in controversy before the
Supreme Court at the time of this amendment will be sent immediately to the
Senate, which will constitutionally proceed to establish them in a definitive
manner by legislative decree.

The amendment was effective upon publication, December 8, 2005.

Lowell G. McManus
Leesville, Louisiana, USA