States take their borders seriously. But should they treat other states as foreign lands? Some of them seem to be moving in that direction.

Most notably, it’s become common to have one state block official travel to another. Numerous blue states and big cities barred their employees from traveling to North Carolina last year, after that state passed a bill that eliminated anti-discrimination protections for LGBT individuals. The California Legislature went so far as to codify the policy, calling on the state attorney general to determine which states have laws on the books that, in the AG’s opinion, discriminate against LGBT individuals. The law took effect this year. Four states were quickly placed off-limits. In June, four more were added to the list. “Public taxpayer dollars should not subsidize discrimination, period,” says state Rep. Evan Low, the sponsor of the California law. “The allocation of our tax dollars is an expression of our values.”

Low’s law and its effects have drawn predictable criticism from officials in the states that are being shunned. They argue that California should mind its own business. Resolutions have been filed calling for retaliatory bans on travel to the Golden State. “It’s fascinating that the very same West Coast liberals who rail against the president’s executive order that protects us from foreign terrorists have now contrived their own travel ban aimed at punishing states that don’t fall in lockstep with their far-left political ideology,” said Matt Bevin, the Republican governor of Kentucky, in a statement. Kentucky is one of the states on California’s no-go list.

Progressive groups have used the travel ban as evidence that policies such as “bathroom bills” regulating which gender can use which facilities are not just wrong, but also harm a state’s economic interest by chasing away visitors. “We’ve seen in other states like North Carolina, when these travel bans go in effect, it does not get any better,” Louisville, Ky., Mayor Greg Fischer has said. “It just leads to more and more bad announcements,” such as convention cancellations and the relocation of big-ticket sports events.

There’s some truth to that. A survey of event planners conducted last year by Meetings and Conventions, a trade magazine, found that half of them take LGBT policies into account when selecting sites. For some meetings, the potential loss of audience members from a market as large as California is reason enough to think about holding the event elsewhere. “Travel planners are faced with logistical nightmares, where attendees and keynote speakers can’t attend,” says Jessica Shortall, managing director of Texas Competes, a business group that promotes LGBT-inclusive policies. “Any kind of uncertainty just pushes them away.”

Such concerns have tanked a bathroom bill effort in Texas. Legislators in August convened a special session to debate the bill, but it died before the session ended August 15. California still bans official travel to Texas, however, because of other policies, including a law allowing adoption agencies to refuse to place children with gay parents.

While the California travel ban has offered progressives ammunition in other states, it has also drawn criticism at home. Some state workers have complained about being barred from necessary meetings and trainings in the targeted states. “Are we putting political correctness ahead of public safety?” asks one emergency management employee.

The travel ban has underlined something that was already clear in this politically divisive age: Different states have different values, even though not all individuals within a state agree on what those should be. When it comes to judging the culture of other states, California has always come in for its share of derision. “We’ve been saying bad things about you all over the country,” British-born singer Nellie McKay recently told a Berkeley audience. “People love to hate you.”