It's one of those national issues that for now is not before the U.S. Supreme Court, but almost inevitably will be before the justices somewhere down the line, even if just in the petition stage.
Sharia, based on the sayings of the Prophet Muhammad, is often a consideration in family issue cases involving U.S. Muslims. But its precepts apply to all aspects of life, and its severest critics allege it is a factor in some acts of terror.
How widespread is the movement to ban Sharia and any foreign law from domestic courts?
Legislators in at least 32 of the 50 U.S. states introduced bills from 2010 to 2012 to limit consideration of foreign or religious laws in state court decisions, the Pew Forum on Religion and Public Life reports.
During those two years, Arizona, Kansas, Louisiana, Oklahoma, South Dakota and Tennessee enacted such bills.
In Oklahoma, the law explicitly banned judicial consideration of Islamic law, or Sharia. The ban was approved by the voters.
The ballot measure read: "This measure amends the State Constitution. It changes a section that deals with the courts of this state. It would amend Article 7, Section 1. It makes courts rely on federal and state law when deciding cases. It forbids courts from considering or using international law. It forbids courts from considering or using Sharia Law.
"International law is also known as the law of nations. It deals with the conduct of international organizations and independent nations, such as countries, states and tribes," the ballot issue read. "It deals with their relationship with each other. It also deals with some of their relationships with persons.
"The law of nations is formed by the general assent of civilized nations. Sources of international law also include international agreements, as well as treaties.
"Sharia Law is Islamic law. It is based on two principal sources, the Koran and the teachings of Mohammed. Shall the proposal be approved?" the ballot read, then offered voters a choice of yes or no.
Seven out of 10 voted yes.
But in 2010, in a challenge brought by Muneer Awad of the Council of American-Islamic Relations, a federal judge struck down the law as unconstitutional, saying it violated the rights of Muslims. A federal appeals court upheld the ruling, and the law was never implemented.
The appeals court said supporters of the law -- State Question 755, or the "Save Our State" measure -- "do not identify any actual problem the challenged amendment sought to solve. Indeed, they admitted at the preliminary injunction hearing they did not know of even a single instance where an Oklahoma court had applied Sharia law or used the legal precepts of other nations or cultures, let alone that such applications or uses had resulted in concrete problems in Oklahoma."
The Pew Forum says the other five states still have their restrictions on court consideration of foreign or religious law. But the laws enacted in Arizona, Kansas, Louisiana, South Dakota and Tennessee are more neutral than the Oklahoma law and do not cite Sharia or other religious laws in particular.
Only 21 of the 92 bills introduced between 2010 and 2012 cite Sharia or other religious laws.
The Brennan Center for Justice at New York University Law School held a symposium on the phenomenon last week in Washington, focusing on "the roots of this movement and the unintended consequences of foreign law bans ... [and] how the current wave of foreign law bans upends the carefully calibrated methods that American courts use to decide whether to apply foreign law, as well as the legal uncertainties these bans could create for families, businesses, and people of all faiths."
Others are far more enthusiastic about such bans.
The American Public Policy Alliance not only supports the bans, but offers a sample legislation for states to follow, adopted in 71 pieces of legislation.
"Granting comity [legal reciprocity] to a foreign judgment is a matter of state law, and most state and federal courts will grant comity unless the recognition of the foreign judgment would violate some important public policy of the state. This doctrine, the 'Void as against Public Policy Rule,' has a long and pedigreed history," the alliance says on its website.
"Unfortunately, because state legislatures have generally not been explicit about what their public policy is relative to foreign laws, including as an example, Sharia, the courts and the parties litigating in those courts are left to their own devices -- first to know what Sharia is, and second, to understand that granting comity to a Sharia judgment may be at odds with our state and federal constitutional principles in the specific matters at issue."
The model legislation offered by the alliance says in part, "Any court, arbitration, tribunal, or administrative agency ruling or decision shall violate the public policy of this state and be void and unenforceable if the court, arbitration, tribunal or administrative agency bases its rulings or decisions in the matter at issue in whole or in part on any law, legal code or system that would not grant the parties affected by the ruling or decision the same fundamental liberties, rights, and privileges granted under the U.S. and [State] constitutions, including but not limited to due process, freedom of religion, speech or press, and any right of privacy or marriage as specifically defined by the constitution of this state."
The alliance offers specific cases in state courts in which Sharia was considered:
"Joohi Q. Hosain [vs.] Anwar Malik, Sharia law of Pakistan, Maryland, 1996: Trial and appellate courts upheld foreign Sharia law and denied mother custody. She lost custody because going to custody hearing in Pakistan would have risked prison, torture or execution."
And "Laila Adeeb Sawaya Malak vs. Abdul, Shariah law of Lebanon/UAE, California, 1986: Appellate court upheld foreign Sharia law and denied mother custody, reversing trial court."
And among others, "Parveen Chaudry vs. M. Hanif Chaudry, M.D., Sharia law of Pakistan, New Jersey, 1978: Appellate court upheld foreign Shariah law, overturned trial court. Wife denied support and child support and division of property; prenuptial agreement signed by parents giving her only $1,500 from marriage upheld by appellate court."
A Pew Forum analysis is far more kindly to Sharia and other religious laws.
"Across the United States, religious courts operate on a routine, everyday basis," the analysis says. "The Roman Catholic Church alone has nearly 200 diocesan tribunals that handle a variety of cases, including an estimated 15,000 to 20,000 marriage annulments each year. In addition, many Orthodox Jews use rabbinical courts to obtain religious divorces, resolve business conflicts and settle other disputes with fellow Jews. Similarly, many Muslims appeal to Islamic clerics to resolve marital disputes and other disagreements with fellow Muslims.
"For the most part, religious courts and tribunals operate without much public notice or controversy. Occasionally, however, issues involving religious law or religious courts garner media attention. ... Meanwhile, [state] bills aimed at banning the use of Islamic [Sharia] law -- or at restricting the application of religious or foreign law in general -- have been introduced in more than 30 state legislatures."
The analysis says, "Disputes over the laws of various religious traditions have occasionally made their way into U.S. civil courts, but the [U.S.] Supreme Court consistently has ruled that judges and other government officials may not interpret religious doctrine or rule on theological matters. In such cases, civil courts must either defer to the decisions of religious bodies or adjudicate religious disputes based on neutral principles in secular law."
Disputes "within a faith tradition often are settled amicably or adjudicated by the religious community itself without involvement from religious or secular courts. Indeed, many religious groups encourage members who are accused of [non-criminal] moral wrongdoing or who are involved in a financial dispute with another member of the religious group to engage in mediation in an effort to come to a voluntary agreement. In many cases, more formal tribunals and the like are employed only after such efforts at mediation fail."
A piece written by Daniel Mach, director of the American Civil Liberties Union's program on Freedom of Religion and Belief, and Jamil Dakwar, director of the American Civil Liberties Union Human Rights program, is highly critical of the state bans.
The piece appeared on the Religion News Service, and was posted on the Huffington Post website earlier this month.
"A discriminatory and wholly unfounded idea is taking root in state legislatures across the country: attempts to pass laws that would explicitly and unnecessarily ban state courts from applying or even considering Islamic, or Sharia, law," the article said.
The article said the outlawed Oklahoma law and others like it contain "prohibitions on 'international law' and 'foreign law,' nonsensically conflating Sharia with foreign law. Other states, preferring not to wear their bigotry on their sleeves, don't mention Sharia law per se, instead referring only to bans on 'international law.' Their intent, however, is unmistakable."
The article said "these efforts are rooted in the baseless idea that U.S. Muslims wish to impose Islamic law on American courts. Proponents of these misguided measures, which have been introduced in 25 states so far, clearly seek to ride the recent wave of anti-Muslim bias in this country.
"Supporters would have us believe that these laws are designed to uphold the Constitution," the article said. "In reality, these measures distort the protections already provided by the Constitution in ways that harm the rights of individuals, faith communities and businesses.
"Rather than strengthen the Constitution, these measures violate religious freedom and undermine the independence of our courts. Laws like the Oklahoma amendment ignore the fact that there are instances -- such as in the execution of a will, or a dispute over religious property -- that require civil courts to consult religious law. Our existing legal system is well-equipped to determine when courts may properly reference religious law, and also when doing so would cross the line. Banning the consideration of a particular faith's laws entirely is not only discriminatory, but also impractical. ...
"Want to get married in Aruba? Couples who are married outside the U.S. could come home to find that a state court could not recognize marriages conducted under Aruban law," the article said. "Want to adopt a child from abroad? If you thought the adoption process was difficult now, think about what would happen if state courts were unable to consider foreign and international law. ...
"These laws are unnecessary and serve only to do two things: Single out Muslims as second-class citizens and undermine the Constitution," the article said. "If supporters of these measures genuinely wish to protect the Constitution, they would do well to trust the framers' respect for international law and religious freedom -- and not trade away our most precious values for political advantage."
The American Public Policy Alliance, on its website, rips into the ACLU-authored article.
"The article posits a series of disjointed, hypothetical misapplications of the legislative efforts to prevent Sharia from encroaching into our legal system," the website said. "Yet, the authors cite no actual examples of misapplications of laws already passed and in force, in Tennessee, Louisiana and Arizona."