Bonds of common genetic and cultural identity coupled with economic and political goals and dissatisfaction with central governments have long been a historic force underlying regional political alliances and independence movements west of the Mississippi River and south of the Mason-Dixon line. The earliest was the Western Republic purportedly envisioned by Aaron Burr for which he was accused and acquitted of treason. The one success was the Texas independence movement that began as Loya relates as early as 1811 culminating with the Republic of Texas that lasted from 1836 to annexation to the USA in 1846.
A separate Republic of the Rio Grande was the idea of Mexican Federalist leaders in Northern Mexican States and sympathizers in the Republic of Texas to break with the Centralist government of Mexico in 1840 and restore the Federalist Constitution of 1824 abrogated by dictator Santa Anna.
Since El Plan de San Diego in 1917 largely radical separatist ideas for regional alliances have centered around pre-Columbian myth as Aztln or general Mexican civil rights as La Raza and have waxed and waned with probably their highest visibility in the 80s. One of the most recent ideas called La Republica Del Norte was described by Dr. Charles Truxillo, professor of Chicano Studies at the University of New Mexico, who has been called a traitor of the Aaron Burr class by some opponents. Two articles on La Republica Del Norte are here and here.
Similar to the Southwestern United States, the Northern Mexican States have been and are generally the most independent-minded within Mexico. They are the most industrialized, pro-capitalist and probably the most religious. In fact the split between parties in the recent Mexican election probably reflects differences between north and south Mexico. One article points out in agreement with author Loya, Northern Mexico also has the highest concentration of people who are wholly or mostly of Caucasian descent. Southern Mexico is Indian Mexico and seems to be in a state of insurgency more often than not. [Lester D. Langley, MexAmerica Two Countries, One Future (New York Crown, 1988), pp. 4-5]. The latter complaints about Centralist Mexico was in part what precipitated independence movements in early 19th century Texas.
To some a resurrection of the Republic of the Rio Grande idea along the lines of the evolution of the Republic of Texas in the early to mid-19th century may not be a bad idea for current times. That is an alliance of the two regions based on recognition and respect for the dominant common Iberian genetic and cultural heritage of Hispanic peoples of the two regions as pointed out by Loya, inclusion of the minority mix of Anglo (Nordic), Native American, African and other diverse peoples in the regions, common economic and political objectives capitalizing on sympathizers and the best of both countries that border the region, evolution to independence and then eventual annexation of the region to the bordering country offering the most benefits to the common goals of the region. Such was the evolution of Texas in the 19th century except the evolution began from original Hispanic to a Nordic Anglo majority in the period instead of the well-balanced numbers between the two and other diverse populations in current Texas.
Note bene: Aaron Burr lived to see the Texas Revolution of 1836 before his death in the fall of the same year at age 80. He noted with pleasure: "What was treason in me thirty years ago, is patriotism now."
Update: Concerning the issue of historic regional differences in Mexico as reflected in the recent national election, here is a relevant summary. Vote ratios of PAN (Caldern)/PRD (Obrador) in percent were US border states 46/22; north states 48/22; center states 36/34; Mexico City metro 30/49; south 20/46; and Yucatn 39/25. (The percentages for the PRI's Madrazo who got 22% total, only 15% in Mexico DF, not shown). In essence, the vote reflects historic Federalism versus Centralism for which domination by the latter led to the unrest and independence of Mexican Texas and eventual annexation to the USA.
Note how the independent and free-spirited Yucateos remain a regional exception even though they are a southernmost state. The home of first Vice-President of the Republic of Texas, co-designer and first signer of the Constitution of 1824, Lorenzo de Zavala, and the one distal state that Secretary of the Republic of Texas Navy, Samuel R. Fisher thought was important enough to defy President Houston and go to their aid in defiance of centralist dictatorship with the Republic of Texas Navy.
