More than half — 63% — of Texans say the sex listed on an original birth certificate should be the only way to define gender, according to a University of Texas at Austin survey.
About a quarter — 26% — said no, while 11% said they were unsure.
Broken down by party, Republicans (87%) and independents (64%) agreed with the statement, but just 35% of Democrats said the same. Just more than half — 51% of Democrats said an original birth certificate should not be the only way to define gender.
The survey was published a week after Oklahoma banned nonbinary gender identities on birth certificates, becoming the first U.S. state to do so.
The legislation, which cleared the Oklahoma state legislature in recent weeks, states: "The biological sex designation on a certificate of birth issued under this section shall be either male or female and shall not be nonbinary or any symbol representing a nonbinary designation including but not limited to the letter 'X.' "
The law takes effect immediately as it passed with emergency designation.
Oklahoma's Department of Health last year first permitted nonbinary markers on birth certificates as part of a lawsuit settlement, a decision reversed by Oklahoma Gov. Kevin Stitt via executive order.
The State Department earlier this month started giving U.S. citizens the option to select X when identifying their genders on U.S. passport applications.
"Transgender people are some of the bravest Americans I know, and our nation and the world are stronger, more vibrant, and more prosperous because of them," President Joe Biden said in a presidential proclamation last month marking Transgender Day of Visibility. "To transgender Americans of all ages, I want you to know that you are so brave. You belong. I have your back."