De Llano was characterized as a sympathetic liberal politician with an independent feeling for his region. He introduced various well-known controversial regionalist like Santiago Vidaurri to his political team. On January 17, 1840, as state governor, he declared Nuevo León independent from Mexico and set the goal of eventually joining the states of Coahuila and Tamaulipas in the Republic of the Rio Grande; however the rebellion collapsed within the year.
