It’s establishing a state minimum RFB. Just like requiring streets to be designed by PEs limits bidding option from those who are perfectly capable of the job from bidding because they lack the stamp.

So they’re being eliminated for not meeting qualifications, not for their speech. Furthermore, they’re usually eliminated from consideration by municipal, county, and school governments, who didn’t write the rule. So the body that wrote the rule (state) isn’t perecuting companies directly.

It creates difficulty in establishing standing to sue. It’s the state’s rule that limits the authority of the cities, so the anti-Israel companies have no standing to sue the state. But the cities also can’t sue the state because they can’t show damages caused by the discrimination since there’s a thousand other bidders who can do the job.

The assholes in the Texas legislature specialize in drafting discriminatory laws that are difficult to challenge in court.