Austin can't claim taco primacy. That category is too broad, encompassing too many variations in style.
When it comes to breakfast tacos, however, Austin trumps all other American cities.
Roberto Espinosa, proprietor of Tacodeli and the breakfast taco interpreter of the moment, espouses a slacker consumer theory of why Austin - a city thick with creative folk, techies, students and politicians - has embraced breakfast tacos.
"People wake up at all hours of the day," Espinosa, a native of Mexico City, said as he served a taco, piled with scrambled eggs and drenched in a puree of russets and jalapenos that he calls Mexican mashed potatoes.
"Maybe the first meal of their day comes at 11 in the morning, and maybe it comes at 2 in the afternoon," Espinosa said, as customers queued for migas tacos, bound with jack cheese. "They want a taco, and they want breakfast. And a breakfast taco gets you both."
Breakfast tacos - eaten by early-morning commuters and third-shift laborers, as well as rock 'n' roll club kids - sound Mexican. Some ingredients, like refried beans and chorizo, taste Mexican. And Mexican-Americans own many of the restaurants that serve them.
But breakfast tacos may owe as much to the American fast-food industry as they do to the taquerias of, say, Guadalajara.
No one agrees on which cook popularized them. Nor is there agreement that Austin was the locus of the development; San Antonio and other cities in the Southwestern United States also claim them.
One recent morning, as Robert Vasquez - proprietor of the Tamale House - rang up 85-cent breakfast tacos of loosely scrambled eggs and hard-fried bacon tucked inside flour tortillas, he recalled the late 1970s, when he opened his take-away spot. That's also when he began serving egg and refried bean tacos. Vasquez guessed that, by the 1980s, breakfast tacos where going mainstream in Austin.
Robb Walsh, an author of a number of books on Texas foods, explained, "They were a way for Tex-Mex joints to compete with Egg McMuffins."
Today, breakfast tacos are this city's totemic food.
"They're cheap, they're good, they're Austin," Vasquez said.
Arkie's Grill, a biscuits-and-gravy sort of place that has been in business since 1948, sells sausage-and-egg breakfast tacos. Polvos, a restaurant that interprets "interior Mexican" cuisine, serves ham-and-egg tacos. Coffee shops across town stock coolers and steam tables with bean-and-egg tacos distributed by Tacodeli, a local quick-service restaurant group.
Porfirio's, open since 1985 and housed in a white cinderblock coop, is a typical working-class purveyor. It serves chorizo-and-egg tacos, bacon-and-refried-bean tacos and 17 other breakfast tacos.
Wrapped in tinfoil, stuffed in white paper bags for carryout, Porfirio's chorizo-and-egg tacos and bean-and-bacon tacos are paragons of the Austin form.
That means they cost less than $2. They're built on flour tortillas. And they're girded with ingredients that stray from conventional notions of Mexican food.
Sausage figures large in the Austin breakfast taco canon. Chorizo, colored with paprika, is a constant. So is Jimmy Dean breakfast sausage.
Jalapeno Joe's, on the same stretch of Airport Boulevard as the Tamale House, recently advertised a 99-cent breakfast taco happy hour and heralded the Jimmy Dean provenance of their sausage.
That's the Austin breakfast taco: inspired by Mexico, but not Mexican, a composite food reflecting two cultures.
Some breakfast tacos served at Austin cafes, bodegas and taco trucks track a path back to Mexico, where, broadly speaking, breakfast tacos are not a food category.
Taqueria La Flor, a baby-blue trailer, serves nopales and eggs on house-made corn tortillas. La Mexicana, a 24-hour panaderia, dishes feathery flour tortillas topped with molten refried beans.
The next steps in the breakfast taco's evolution are occurring on the margins of Austin's Mexican-American community.
Torchy's Tacos, which began in a gray trailer plastered with pitchfork-wielding baby devils, is an Anglo-owned enterprise. It serves migas tacos, made with a scramble of eggs and strips of fried corn tortillas, pocked with green chilies, capped with avocado slices, enveloped by flour tortillas.
At El Chilito Tacos y Cafe, University of Texas students eat ham-and-egg-filled breakfast tacos while drinking soy milk lattes.
Further afield, geographically and culturally, is Donut Taco Palace II, operated by Pisey Seng, born in Phnom Penh, Cambodia. She sells doughnuts, sausage-and-jalapeno-stuffed croissants, Czech-inspired pastries called kolaches, and breakfast tacos. They're filled with everything from migas to nopales to Jimmy Dean and eggs.
When asked why she chose to sell breakfast tacos from a strip-mall shop, decorated with glossy photographs of Angkor Wat, Seng said, "We wanted to be different from everybody else."