The federal government has winnowed a list of potential builders of President Trump’s wall on the border with Mexico from a couple of hundred applicants to about 40 firms, which now have until May 30 to submit full design proposals. From those submissions, U.S. Customs and Border Protection officials will select a handful of finalists to build prototypes at the Otay Mesa border crossing in San Diego. But if a piece of ill-advised legislation is approved in Sacramento, winning bidders who work on the California section of the wall could find themselves barred from any future state construction contracts.

SB 30 is one of several bills introduced when the current legislative session began in December that were responses to Trump’s election. Some of them make sense, such as SB 54, which would bar state and local police, schools and other agencies from voluntarily assisting federal immigration enforcement officials. Or SB 6, which would allocate money for immigration-law organizations to provide legal advice for undocumented people during deportation proceedings.

But SB 30 is an overreach that would penalize businesses that are doing nothing wrong and breaking no laws.

We have been loud and steady in denouncing Trump’s border wall, a singularly silly idea that will do little to deter illegal immigration. Traffickers will find other routes, and, besides, a growing share of the population living in the U.S. illegally entered the country with valid visas — rather than by sneaking over the border — and then simply didn’t leave. Overall, the number of people living in the country illegally has declined over the last decade.

But it is possible to oppose the border wall without supporting SB 30. The bill would punish contractors and other businesses for seeking work and doing their jobs — just because some state political leaders dislike the project they’re working on.