In the 1930s a pentecostal preacher headed for the Mezquital plain in Hidalgo where he had little success in gaining converts. Traveling out to the villages, the populace rejected him (at times with violence) and he found himself in the town of Ixmiquilpan - what passes for a "big town" in the area. There he had some success gaining converts and, with the help of the army, he built a chapel and started a religious colony - Colonia Evangelica. The Summer Language Institute supplied Otomi bibles, and the congregation was set.
Jobs in the colony were parceled out to members only, and such an offer brought in converts from the pueblos that had previously rejected the preacher. Once migrants were converted and given jobs, missionaries easily penetrated their home pueblos and gained more converts in the area. Of course, the PRI was the political patron of the Pentecostals, and with institutional support, Pentecostalism throve in the area.
Flash forward to 2005. When a prominent Pentecostal preacher died, Catholics refused to allow him burial in the local municipal cemetery - mostly because they claimed he had never contributed to the upkeep of the place. Evangelical Christians in Hidalgo organized a protest in response, blockading the highway to Pachuca and shutting down trade and business along the route until the governor of Hidalgo offered to meet with them. However, in elections just a short time later, PRIistas were handed their heads - on plates - by an Evangelical voting bloc that sent a message to the parties - support our causes or find yourself on the loosing end of the vote.
With presidential elections two years away, and evangelical christian growth in Mexico growing steadily, we may be looking at a new player in Mexico's national elections - not just on the regional level.
For more on the topic, see Guillermo de la Pena's "El Campo Religioso, La Diversidad Regional." See also Joseph Contreras' In the Shadow of the Giant: The Americanization of Mexico, chapter 12 called "The Evangelical Challenge." Contreras, as a reporter, gets a little melodramatic at times, and could certainly use a history lesson or two, but it is an interesting book to chew on.