New residents coming from California and other places, however, could pose a long-term threat to Texas’ winning formula of low taxes, mild regulation, and limited government spending. The danger stems from the seldom-noted difference between voting with one’s feet and voting with one’s ballot.

The economic contrasts between California and Texas are vivid. California’s taxes are high, but not high enough to prevent large and persistent budget deficits that result from the state’s exorbitant government spending. An army of state regulators, equipped with an arsenal of regulations, practically dares anyone to start a business or hire more workers to expand an existing one.

More and more Californians, both as consumers and producers, are concluding that pleasant weather and attractive scenery aren’t worth the tax burden and high cost of living. They’re voting with their feet by leaving the state, with Texas the most popular destination. Between 2004 and 2010, net migration from California to Texas totaled about 185,000 people—over a quarter of the Lone Star State’s overall gain.

Most of us understand that voting with one’s feet depends heavily on economic benefits and costs. Someone contemplating a move from California to Texas has good reason to weigh those factors carefully because his “vote” determines whether he receives those benefits and incurs those costs. His vote is decisive—he ends up in Texas because—and only because—he “voted” to do so.

California voting | Economic benefits, however, aren’t the only consideration when voting with one’s feet. Political ideology can also be important. Assume, for example, that many Californians are sympathetic to arguments for ambitious spending programs, the high taxes that support them, and tough regulations on businesses. For those people, at least part of the value of living in California lies in policies consistent with their liberal sympathies.

When Californians consider the choice of moving to Texas or remaining in California, they weigh a dollar’s worth of economic benefits the same as a dollar’s worth of ideological benefits. Those who grumble about high taxes and big government will be the first to pack up and leave. They’re already in a Texas state of mind, and this may lead to the casual assumption that newcomers won’t change Texas’ politics. However, in time the economic benefits of moving will convince even political liberals that Texas offers a better deal. Yet they arrive in Texas clinging to California’s political ideology, apparently not realizing the connection between Texas’ politics and its economy. Having voted with their feet, these former Californians start voting with their ballots—to express their opinions and preferences. This shifts the relative importance of economic and ideological benefits in a way that’s rarely appreciated.

Voting with her feet, the individual gets exactly what she chooses. Voting at the ballot box is another matter. In statewide elections, the chance that the policy will pass only because she votes for it is effectively zero. Weighted by this tiny probability, her personal cost of voting “yes” in terms of the new policy’s higher taxes and prices becomes so small that she can ignore them with impunity. This holds even if passage of the new policy imposes high total costs on the voter.

Take, for example, a referendum to impose a Texas state income tax to fund noble-sounding programs. As a matter of principle, most Texans oppose an income tax—a sentiment that may not be shared by voters relocating from California. If the tax passes, it will cost our hypothetical California transplant $10,000—a cost that might dissuade all but the most liberal voters. A “no” vote thus seems certain—except for the tiny probability that her vote will decide the election’s outcome.

Assume the probability that our transplanted Californian’s vote will alter the referendum’s outcome is one in 100,000. Her expected cost of voting “yes” would thus equal a dime. So the voter would favor a Texas income tax if she realizes more than a dime’s worth of ideological satisfaction from expressing her support for the political preferences she brought from California. The typical Texan faces the same low cost for ideological satisfaction, but he’s more likely to adhere to Texas traditions, favoring lower taxes and limited government.

The important insight of expressive voting is that a little bit of ideological satisfaction can sway voters to cast their ballots in favor of policies with high personal costs. It explains why people commonly ignore their economic interests to further political agendas they favor. Rich people vote for policies that raise their taxes. Private sector workers vote to increase public sector workers’ pay, even if it means higher taxes. Parents vote to maintain public school monopolies that reduce educational quality. Old people vote for reducing future global temperatures, although that means higher energy bills today.

This voting seldom comes from deep commitments to carefully examined policy positions. Instead, it reflects the opportunity for voters to feel good about their generosity by casting a vote that effectively costs them nothing. If enough voters indulge their feelings, the policies win political approval and everybody foots the bill.

Californians aren’t the only newcomers attracted to Texas. Others are arriving from New York, Illinois, Michigan, Ohio, New Jersey, and countries all over the world. It’s highly unlikely that most of them will share Texans’ ideological ethos. Once in Texas, many of those newcomers will see a net benefit in voting for policies that will in time undermine the economic factors that drew them to Texas in the first place.

Maybe it’s time to scrape off the anti-litter “Don’t Mess with Texas” bumper stickers and replace them with “Don’t Californize Texas.”