â€œI donâ€™t believe in an America where the separation of church and state is absolute,â€ Republican presidential hopeful Rick Santorum declared in a February 26 interview with ABCâ€™s This Week. â€œWhat kind of country do we live in that says only people of nonfaith can come into the public square and make their case?â€

What is the former Pennsylvania senator talking about? Doesnâ€™t appearing on a national news program while seeking the presidential nomination of a major political party qualify as making your case in the public square?

Santorumâ€™s comments were prompted by the latest brouhaha over the role of religion in politics. In January the Obama administration unveiled new health care regulations that require organizations run by the Roman Catholic Church to offer health insurance that covers womenâ€™s reproductive services, including contraception. The U.S. Council of Catholic Bishops denounced the mandate as a violation of the First Amendmentâ€™s ban on laws â€œprohibiting the free exerciseâ€ of religion.

The Obama administration tried to limit the political damage by claiming that covering contraception would, on balance, save insurers money by reducing claims related to pregnancy and birth. Hence insurers could offer the coverage at no additional cost to them or their customers, meaning the Catholic Church would not actually have to pay for contraception. That argument is bunk: money saved but not rebated as a lower fee is not really distinguishable from paying for the covered service.

As the contraception controversy illustrates, conflicts between church and state in this country typically arise from the way that benefits supplied or mandated by the government are distributed. University of Virginia law professor Douglas Laycock, who has spent a career looking at the interaction between government and religion, highlights Supreme Court Justice Hugo Blackâ€™s formulation in the 1947 case Everson v. Board of Education.

Writing for the 5-to-4 majority in Everson, Black declared, â€œNo tax in any amount, large or small, can be levied to support any religious activities or institutions, whatever they may be called, or whatever form they may adopt to teach or practice religion.â€ So far, so good. But Black also argued that government â€œcannot hamper its citizens in the free exercise of their own religion. Consequently, it cannot exclude individual Catholics, Lutherans, Mohammedans, Baptists, Jews, Methodists, Nonbelievers, Presbyterians, or the members of any other faith, because of their faith, or lack of it, from receiving the benefits of public welfare legislation.â€ The Court therefore ruled that New Jerseyâ€™s policy of reimbursing parents for bus transportation to and from parochial schools did not violate the First Amendmentâ€™s ban on â€œan establishment of religionâ€ because the state was merely supplying a general service to all schools.

When the Constitution was adopted in the 18th century, Justice Blackâ€™s two principlesâ€"1) citizens cannot be taxed to support religious activities, and 2) the state may not deny tax-financed public welfare benefits to any citizen based on his religious beliefsâ€"rarely conflicted. â€œIn an era with few public welfare benefits,â€ Laycock explained in a 2006 essay from his collection Religious Liberty, â€œno-aid [to religious activities] protected citizens from being forced to contribute to churches involuntarily: it protected the churches from financial dependence on government, and thus from government control.â€

But with the relentless expansion of the welfare state, this separation of church and government transfers became a thing of the past. In their 1997 book The Challenge of Pluralism, political scientists Stephen Monsma of Calvin College and J. Christopher Soper of Pepperdine University argued that government funding of secular nonprofit public service programs places similar religious programs â€œat a government-created disadvantage.â€ This claim makes sense only if one assumes that government agencies are engaged in teaching religious or nonreligious beliefs as they dispense food stamps, rent vouchers, and vaccines. A cynical public choice analysis suggests that both churches and government welfare agencies may see themselves in competition when it comes to increasing the number of people who are dependent upon them.

To address concerns that religious organizations are â€œdisadvantagedâ€ by competition with secular welfare agencies, recent administrations have devised ways to shower tax dollars on various faith-based initiatives. The total amount of tax money involved is hard to determine. But Catholic Charities affiliates, for example, received more than 60 percent of their budgets (nearly $3 billion) from government sources in 2010, while only 3 percent came from diocesan church contributions. Subsidizing a religious groupâ€™s welfare activities, of course, frees up other funds to be used for nonsecular purposes.

There is a way to call a ceasefire in Rick Santorumâ€™s culture war. As Monsma and Soper observe, â€œGovernmentâ€™s advantaging of the secular over the religious could be avoided if government would simply stay out of a given policy area.â€ But they think there is no way to untangle the contentious church/state social service mess into which weâ€™ve gotten ourselves. Here they are wrong.

Consider public education. States and localities could collect tax dollars as usual and then offer school vouchers that parents could use to send their children to whatever religious or secular school they choose. States likewise could use vouchers to subsidize higher education, rather than running their own universities.

What about health insurance? The tax code could be reformed so that employers give their workers cash instead of medical benefits, allowing individuals to select the private health plan that works best for them, deciding for themselves whether they want coverage for contraception, abortion, sterilization, stem cell treatments, and so on. The poor could receive tax-financed vouchers to buy whatever private insurance they prefer. In fact, most public welfare services, including job training, nutrition support, and drug treatment, could be converted into voucher programs.

Religious groups have always been welcome to make their cases in the public square, but if churches want to be left alone, they should stop begging for alms from the government. Rick Santorum should heed Ronald Reaganâ€™s admonition. â€œWe establish no religion in this country,â€ Reagan declared in 1984. â€œWe command no worship, we mandate no belief, nor will we ever. Church and state are, and must remain, separate.â€

Science Correspondent Ronald Bailey is the author of Liberation Biology (Prometheus).