There are Anglo and (a few) Cajun settlers out east, German settlers in OTL Hill country. The Western and Southern areas are a Hispanic majority.
Alright I'll give it a shot and edit it from there (note, the spanish here is all google translate so its almost guaranteed to be wrong). This is sorted by membership numbers and not seats by the way.
All parties officially go by both their Spanish and English name (though they're most commonly referred to their Spanish names or the spanish acronym's i.e. PDC.
Political Parties of Tejas (
Texas):
Dominant Party:
Partido Demócrata Cristiano (Christian Democratic Party) - Right Wing (Social Conservatism, Christian Democracy, National Conservatism, Tejas Nationalism, Right-Wing Populism, Economic Populism)
The Dominant Party in Tejas and the one that more often then not forms power. Their attitudes match that of the majority of the people, socially conservative and a bit economically populist (however leaning to the right most of the time). The party has a strict anti-communist past as well. They're spending their first term out of power in decades after this years election.
Major Party:
Liberales (Liberals) - Centre (Neoliberalism, Economic Liberalism, Social Liberalism, Third Way)
Usually the 2nd largest party in the parliament, they are a free market, neoliberal party that advocates FTA and a market free economy as well as some social reforms. Typically very popular in the inner metropolitan areas of Tejas such as Bexar, Buffalo and San Elizario (where the party's HQ is).
The party has won government for the first time in over 30 years with Beto O'Rourke leading the party to victory in coalition with La Izquierda, Deutsche Rechte and Partido Agricultores, with a 15% swing against the PDC (with the PDC winning 58% last election to Liberales 26%, this time PDC won only 43% and Liberales won 35%.
Minor Parties:
La izquierda (The Left) - Left-Wing (Progressivism, Social Democracy, Democratic Socialism, Green Politics, Eco Socialism, Green Socialism, Left-Wing Populism)
Founded 10 years ago by some students, La Izquierda began as a protest party but has become very popular with the under 30 vote, with the party representing the youth which want change in the traditionally conservative country. They advocate a wide range of social changes that are considered rather extreme by Tejas standards such as Same-Sex Marriage, Abortion Rights and Gun Control.
Deutsche Rechte (Derechos Alemanes, German Rights) - Big-Tent (German Minority Interests)
A Big tent party for the German minority. They're typically a more minor party (roughly the same size as La Izquierda) as most of the German minority either vote for the PDC or Liberales.
Partido Agricultores (Farmers Party) - Right-Wing (Agrarian Politics, Agrarian Conservatism)
Fairly self explanatory, represents farmers interests within Tejas. They typically caucus with the PDC, however have decided to enter into a coalition with the Liberales for this term (after dissatisfaction with the PDC's inaction and Liberales promising certain tariffs on international dairy and food products and subsidies for domestic produce). Typically are socially conservative, matching with the attitudes in rural areas.
Tiradores y Cazadores (Shooters and Hunters) - Right-Wing to Far-Right (Pro-Gun Rights, Anti-Gun Legislation, Anti-Animal Protection, Pro-Hunting)
Formed by a former PDC member, the party has a singular focus on protecting the rights that gun owners currently have. The party was formed in part because of the pressure applied from Liberales and to a lesser extent, La Izquierda and even Deutsche Recthe for some level of gun control.
Micro Parties:
El Movimento (The Movement) - Syncretic (Pirate Politics, Direct Democracy, E-Democracy, Freedom of Information, Network Neutrality, Open Government)
The movement is the other party of some significance that has found its way from student politics. The Party hosts a wide range of Pirate Politics, with the main one being more direct democracy and open government as well as regarding Freedom of Information and Net Neutrality crucial.
Partido Demócrata Nacional (National Democratic Party) - Far-Right (Tejas Nationalism, National Conservatism, Economic Nationalism, Protectionism, Right-Wing Populism, Anti-Immigration)
Formed by a former PDC member who thought that the CDP wasn't right-wing enough (which is rather hard to believe but that's another story), the party is very nationalistic and very protectionist in its economic policy, they also want an almost complete halt to immigration (despite the CDP having immigration at very low levels to begin with). The party hasn't gained that much traction, with the party rife with infighting, as well as being rather divisive in nature and rhetoric, even for Tejas (having a properly islamaphobic streak to them and being called outright racists by a sizeable amount of the people).
Partido Comunista de Tejas (Communist Party of Tejas) - Far-Left (Communism, Tejas Communism, Marxism-Leninism, Pacifism, Scientific Socialism)
The boogeyman of Tejan politics, the Communists are easily the most disliked political entity in the country (and thats mainly from the right, the left aren't that concerned with them). They want to abolish the traditional political system and want to introduce a fully socialist system. The Party was banned for a period between the 20's and 30's (during the height of the popularity of Socialism in Tejas) and then between the 50's and 80's (that was mainly due to a conservative government). The party for the large part is completely irrelevant however, having failed to gain more than 2% at any election since the late 90's (with them getting only 1.8% of the vote at the last election).