From 1848 until Richard M. Nixon's victory in 1972, Texas voted for the Democratic candidate for president in every election except 1928, when it did not support Catholic Al Smith.
In the post-Reconstruction era, by the late 19th and early 20th centuries, the Republican Party became non-competitive in the South, due to Democratic-dominated legislatures' disenfranchisement of blacks and many poor whites and Latinos.