What event marked a significant change in how Texans began to vote not only in presidential elections but also in state elections?

The significant change in how Texans began to vote in both presidential and state elections was marked by the passage of the Voting Rights Act of 1965. This landmark legislation aimed to eliminate racial discrimination in voting, leading to increased voter registration and participation among African Americans and other minority groups in Texas. The Act's enforcement provisions helped dismantle barriers such as literacy tests and poll taxes, fundamentally transforming the electoral landscape in the state. Consequently, the increased political engagement of previously marginalized communities reshaped the dynamics of Texas elections.