Eight companies with perfect scores on the Human Rights Campaign's Corporate Equality Index have contributed money to the campaign of Texas Republican Sen. Donna Campbell (above right), the author of legislation that seeks to enshrine a "license to discriminate" in the state Constituion.

But none of these otherwise gay-friendly companies have come out in opposition to SJR 10, which Campbell filed early last month.

The Texas Observer reports:

“SJR 10 is one of thousands of bills filed, we will weigh in and comment on bills when and if they are scheduled for hearing,” said Mona Taylor, a spokeswoman for Dallas-based AT&T Inc., which contributed $5,000 to Campbell's campaign through its PAC this year.

Other companies with perfect HRC scores that have contributed to Campbell's campaign in the last year include General Motors Co. ($2,500), Citigroup Inc. ($1,500), UnitedHealth Group Inc. ($,1000), the Raytheon Co. ($1,000), Merck & Co. ($1,000), Genentech Inc. ($750) and Astellas Pharma Inc. ($500).

On Monday, Plano added itself to the list of cities in Texas that have passed ordinances banning anti-LGBT discrimination. Two days later, state Rep. Jason Villalba, R-Dallas (above left), filed a House version of Campbell's "license to discriminate" bill — and another lawmaker is threatening to introduce a similar measure, The Observer reports.

Experts say the legislation would severely limit cities' ability to enforce nondiscrimination ordinances, since any business owner could claim an exemption if they have "a sincerely held religious belief." But the unintended consequences of the constitutional amendment could be far worse, according to Equality Texas' Daniel Williams.

Texas already has a statute, known as the Religious Freedom Restoration Act, that provides strong protections for religious freedom. But the proposed amendments would supplant the RFRA and go much further, overriding the statute's exceptions for things like zoning regulations and civil rights laws, according to The Observer:

“A church or a synagogue or a mosque could conceivably be built anywhere with no concern to traffic flow or how much parking is available or building codes,” Williams said. “There are butchers that butcher in accordance with very specific religious laws, and they're able to do that, but the city and the state enforce environmental protections that ensure we don't wind up with giant ponds of blood in residential neighborhoods. If you take away the ability of cities to enforce those, it's going to have an enormous negative impact on the quality of life for everyone in that area.”

Williams said Campbell has introduced similar measures in three previous legislative sessions. Given the senator's penchant for seeking to enshrine a "license to discriminate" in the state Constitution, the companies' campaign contributions could reasonably be interpreted as an endorsement of the legislation — at least until they publicly state otherwise.