What stops Texas from sliding into authoritarianism after independence?

The same things that stop it now, only closer and more accountable: a written constitution, separated powers, independent courts, a Bill of Rights, and free elections that let the people remove anyone who overreaches. Independence does not weaken those guardrails. It puts them fully in the hands of Texans.

The guardrails are already built and already in force

Texas does not start from a blank slate where a strongman could simply take over. It begins with a constitution that has governed for generations, a Bill of Rights that protects free speech, religion, due process, property, and the right to keep and bear arms, courts that can strike down unlawful acts, and regular elections. All of that is in force today and carries straight through independence. A would-be tyrant in an independent Texas runs into the same wall of law and institutions that exists now, with no distant federal patron to appeal to.

Power is split on purpose

The Texas Constitution does not gather power in one place. Article 2, Section 1 divides the powers of government into three distinct departments, legislative, executive, and judicial, and forbids anyone in one department from exercising powers that belong to another, except where the constitution expressly allows it. That separation is a deliberate barrier against one person or faction seizing control. It is written into the document Texas already lives under, and it does not vanish when Texas governs itself. If anything, it answers directly to Texans instead of being one layer among several.

The people hold the ultimate check

In Texas, power is not granted from the top down. Article 1, Section 2 of the Texas Constitution states that all political power is inherent in the people. The people elect their representatives, and the people can vote them out. An official who tries to grab more than the law allows faces the most basic check there is: the next election, and the courts in the meantime. Authoritarian rule requires silencing or sidelining the public. A system built on the consent of the governed, with frequent elections and protected speech, makes that extremely hard to do.

Consent is the foundation, and consent can be withdrawn

The entire premise of Texas independence is government by the consent of the governed, the same principle Texans would invoke to leave the union. A people who built their nation on the right to alter or reform their own government do not surrender that right the day after independence. It remains the ultimate safeguard. The same power that frees Texas keeps Texas free, because a government that rules without consent has no legitimate claim to power under Texas's own founding ideas.

The bottom line

What stops authoritarianism is what stops it in any free republic, a constitution, divided powers, independent courts, a Bill of Rights, and elections, and in an independent Texas all of it answers to Texans directly. Self-government is not a step toward tyranny. It is the strongest defense against it.