Republicans in Texas want to roll back the clock on marriage rights for transgender people.

SB 723, sponsored by state Sen. Tommy Williams (R), would bar district clerks from accepting a court order recognizing a sex change as legal documentation for a marriage license. In effect, the bill would force clerks to recognize a 1999 appeals court ruling that said a person's gender at birth sticks with them for the rest of their life even if they have a sex change.

"If SB 723 gets a favorable vote it will enshrine Littleton vs Prange (1999) logic -- you are what the doctor put on your birth certificate -- into Texas State law," according to the Human Rights Campaign's Meghan Stabler, who is also a transgender woman from Texas.

Advocates worry that if the law is enacted, it could even nullify existing marriages.

"It appears the goal is to try to enshrine a really horrifying ruling and making it law in the state of Texas," Houston attorney John Nechman told The Associated Press.

"This bill is unprecedented anywhere in the country," Shannon Price Minter, an attorney with the Transgender Law & Policy Institute, told Raw Story. "No state has ever passed a law recognizing the existence of transgender people, then tried to take it back."

In 2009, Texas Democrats reportedly threatened to kill a bill authored by state Rep. Lois Kolkhorst (R) if it did not include language that allowed for a "court order of sex change" to be accepted for getting a marriage license. A spokesman for Kolkhorst told Raw Story that the congresswoman was now sponsoring legislation that would reverse those rights but denied she was targeting transgender people.

"We have a bill that actually would remove the transgender component from it as well but it's not specifically speaking to that issue," Kolkhorst chief of staff Chris Steinbach said.

For his part, Gov. Rick Perry (R) has indicated that he will sign the bill into law if it makes it to his desk. Perry spokesman Mark Miner said that the bill is intended to "clarify the unintended consequences" of the 2009 law.

"The practical repercussions of the bill are unclear, but it seems to be a mean-spirited attempt to send a negative message about transgender people. The only certain thing this bill would do is sow confusion," Transgender Law & Policy Institute's Shannon Price Minter noted.