[1] The Texas Triangle is one of eleven megaregions in the United States, clusters of urban areas that share economic and cultural ties.

[6] Beaumont, located east of Houston, has been considered part of the Texas Triangle by numerous studies dating from 2000.

Dr. Robert Lang of the Metropolitan Institute at Virginia Tech characterized Dallas–Fort Worth as one of the earliest recognized megapolitans.

Although each city is distinct, Dallas and Fort Worth developed closely enough to form the urban area widely known as the Metroplex.

They are Anderson, Atascosa, Austin, Bandera, Bastrop, Bell, Bexar, Blanco, Bosque, Brazoria, Brazos, Burleson, Burnet, Caldwell, Chambers, Collin, Colorado, Comal, Coryell, Dallas, Denton, DeWitt, Ellis, Falls, Fayette, Fort Bend, Freestone, Galveston, Gonzales, Grimes, Guadalupe, Harris, Hays, Henderson, Hill, Houston, Jackson, Johnson, Kaufman, Kendall, Lampasas, Lavaca, Lee, Leon, Liberty, Limestone, Madison, McLennan, Medina, Milam, Montgomery, Navarro, Rockwall, Robertson, San Jacinto, Tarrant, Travis, Trinity, Victoria, Walker, Waller, Washington, Wharton, Williamson, and Wilson.

This culminated with Barack Obama flipping Dallas, Harris, and Bexar counties to the Democratic party in 2008.

Travis County also has gone Republican in gubernatorial races, most recently in 1998, when George W. Bush won a second term to the governorship.