Rarely have intraparty battles between Republicans in Texas been as bitter, protracted and consequential as the primary contests culminating in Election Day on Tuesday.

The fights have primarily focused on members of the Texas House who angered many conservative voters last year by impeaching the Republican attorney general, Ken Paxton, on charges of corruption and abuse of office. Mr. Paxton, who was acquitted in the Texas Senate, vowed revenge, and number one in his sights has been the house speaker, Dade Phelan.

Gov. Greg Abbott has also been going after a number of Republicans in the Texas House, seeking to unseat those who opposed his plan to use public money to help families pay for private and religious schools.

Aggressive campaigning by both statewide leaders is amplifying tensions that have simmered for years between the party’s old guard and a more socially conservative faction aligned with former President Donald J. Trump that sees Tuesday’s vote as a chance to shift the balance of power in the Texas House, which has served as a moderating force in the state’s politics.

The fight is not unique to Texas as Republicans across the country and in Congress engage in a struggle for control of the party. But the outcome could reverberate widely if Republicans in Texas, the most populous and wealthiest conservative state, decide the state needs to move even further to the right.

“This is a once-in-a-generation election,” said Nick Maddox, a Republican consultant who is working with Mr. Paxton and for Republican candidates in more than a dozen races.