What was the position of Mexico when it comes to slavery ? explain

In 1829 Mexico abolished slavery, but it granted an exception until 1830 to Texas. That year Mexico made the importation of slaves illegal.

powers  are  denied  to the  national governmentin three distinct ways: some  powers, such as the  power  to levy duties on exports or prohibit the freedom of religion, speech, press, or assembly, are expressly  denied  to the  national government  in the  constitution.