Final answer:
The Texas Constitution requires voter approval for amendments to take effect, while the U.S. Constitution requires ratification by state legislatures.
Step-by-step explanation:
One of the most important differences between the Texas Constitution and the U.S. Constitution is the need for voter approval for amendments to the Texas Constitution to take effect. In Texas, amendments to the state constitution must be ratified by a majority of voters in a public election after being approved by the state legislature. In contrast, amendments to the U.S. Constitution are proposed by a two-thirds vote in Congress and ratified by three-fourths of the state legislatures.