During the course of their rich and exciting history, the people of Texas have lived under seven different constitutions. The constitution of 1876, the one in effect today, is one of the longest and most detailed of all the state constitutions. It created three branches of state government but restricted their power and duties. The legislative branch is comprised of a 150-member house of representative and a 31-member senate. The governor of Texas has less power than governors do in most other states. One of the most important jobs of the state government is making decisions about how to raise and spend large amounts of money.

In Texas, local governments—including counties, cities, and special districts—have considerable power. The business of the county is conducted by a county judge and four members of the commissioners' court. The leadership in city governments may take one of several forms—mayor-council, commission, or council-manager. The most common special district in Texas is the independent school district.

The Texas constitution establishes five levels in the state court system: a supreme court and a court of criminal appeals, courts of appeals, district courts, county courts, and municipal and justice of the peace courts. Criminal cases are governed by the Texas Code of Criminal Procedure, and Texas law provides graded penalties—certain kinds of crimes require certain punishments.

Politics in Texas have changed dramatically over the last 50 years, as shifting party loyalties and new groups of voters have upset the old balance of power. Most Texans belong to one of two major political parties, the Republicans or the Democrats. Both of these parties are organized in the same way, with a permanent party structure and a temporary party structure. The interest groups that lobby government officials in Texas are among the most powerful of any state.

Texas has played an important role in the federal government of the United States. Four Texans have become president, and many others have contributed as leaders of Congress and heads of important executive departments. At the dawn of the twenty-first century, Texas shares a complex interdependence with the federal government in Washington, in areas including energy, the environment, and the economy.