Editor's note: This story has been updated throughout.
At a news conference with Patrick and other supporters of Senate Bill 6, Lucio, who has previously bucked his party on social issues, announced he will vote for the legislation. His announcement kicked off a flurry of activity at the Capitol — both for and against the bill — ahead of its hearing Tuesday in the Senate State Affairs Committee.
Lucio's support means there are now 18 senators — including 17 Republicans — on the record in favor of the legislation. Three Republicans are not among those listed as co-authors of the bill as of Monday afternoon — Joan Huffman of Houston, Jane Nelson of Flower Mound and Kel Seliger of Amarillo. The offices of Huffman, Nelson and Seliger didn't immediately respond to requests for comment for this article.
Senate Bill 6 would require transgender people to use the bathroom in public schools, government buildings and public universities that matches their "biological sex." The legislation would also reverse local nondiscrimination ordinances that let transgender people use the bathroom that corresponds with their gender identity.
"Children, youth and parents in these difficult situations deserve compassion, sensitivity and respect without infringing on legitimate concerns about privacy and security from other students and parents," Lucio said at the news conference.
Lucio, who is from Brownsville, has previously found himself at odds with the Democratic Party. A devout Catholic, he has supported legislation tightening restrictions on abortion in Texas.
Lucio's son, Eddie Lucio III, serves in the House. He issued a statement later Monday saying he respectfully disagrees with his father on the legislation, which he called "nothing more than a political ploy to appease certain narrow-minded constituencies at the expense of some of the most vulnerable and marginalized people in society."
"My father preached love and service in my house growing, and although I sincerely believe that his position is not rooted in hate, it is still wrong and will create adversity for many," said Eddie Lucio III, also a Brownsville Democrat.
Opponents of the bill, including LGBT advocates and members of the Texas business community, have decried it as discriminatory and have warned that it could have dire consequences on the state's economy.
At a separate news conference outside the Capitol on Monday, a coalition of Texas business leaders and tourism officials condemned the bathroom bill.
Tom Noonan, CEO of the Austin Convention and Visitors Bureau, said that 23 organizations had “proactively reached out” to the Austin Convention & Visitors Bureau and said “if you pass this bill, we are going to have to leave.”
That could result in more than $110 million in economic losses, Noonan added.
Phillip Jones, CEO of Visit Dallas, said that billions of dollars are at risk for the state and added that dozens of meeting organizers, including smaller corporate groups, would cancel plans to meet in Texas if this legislation were to pass.
At the earlier news conference, Patrick also announced he was launching “Operation 1 Million Voices,” an effort to build support for the bill among Christians in Texas. Organizers said hundreds of pastors are already involved in the project and will hold events over the next two months across the state.
Patrick was accompanied at the news conference by North Carolina Lt. Gov. Dan Forest, who pushed through similar legislation in his state’s legislature to much controversy last year. Forest, who called Senate Bill 6 “very similar” to the North Carolina law, urged Texas lawmakers to resist warnings of economic doom if they pass Senate Bill 6.
“No businesses left North Carolina,” Forest said. "This is not an economic issue. This is about doing the right thing. There is no price tag you put on a head of a woman or a child in a place of public accommodation.”
Alexa Ura and Sanya Mansoor contributed to this report.