Why have Texas lawmakers from both parties made it difficult for third parties to get a name on the ballot for statewide office?

Must be at a minimum of 350 words but no more than 500.be sure to Select the relevant terms (not all of the terms) and underline and bold them in your initial posting:
Primary elections, electoral cycle, runoff primary, open primary, closed primary, general election, special election, Nineteenth Amendment, suffrage, poll tax, early registration, white primary, Jaybird Party,  Voting Rights Act 1965, motor voter law, early voting, straight-ticket voting, reapportionment, redistricting, preclearance