Magnolia Independent School District is being sued over a policy requiring short hair for boys but not girls.
Texas joins seven other states in passing trans-exclusionary sports legislation this year.
His remarks come as Republicans in Virginia and Texas have voiced opposition to same-sex marriage — six years after marriage equality became law in the U.S.
Rep. James White wrote a letter to the state's attorney general asking for clarification, writing that the U.S. Supreme Court cannot overrule state laws.
The bill passed in the third special session of the legislature this year, and Gov. Greg Abbott is expected to sign it into law.
The governor's office removed the page from the Texas Department of Family and Protective Services website after the governor was criticized for promoting "transgender ideology."
Trans youth and their families turned out in protest, with some as young as 10 speaking out.