In addition to usually losing political fights, creation science supporters also lose in the courts as well. Regardless of what arguments they try to use, the courts inevitably find that teaching creationism is a violation of the separation of church and state because creationists are unable to avoid the fact that their ideology is fundamentally religious and, therefore, inappropriate to teach students in public schools. Only science is appropriate for science classes and that's evolution.
Supreme Court Decisions
The first case came in 1968: Epperson v. Arkansas was over an Arkansas law prohibiting both the teaching of evolution and the adoption of text books which included the concept of evolution. When a Little Rock biology teacher found that a text book adopted by the local school board included evolution, she was faced with a difficult dilemma: she could either use the book and violate state law or she could refuse to use the text and risk disciplinary action from the board itself. Her solution was to remove the problem by getting rid of the law.
When the case reached the Supreme Court, the justices found that the law was impermissible because it violates the Establishment Clause and prohibits the free exercise of religion. Its only purpose was to prevent the teaching of a scientific concept which conflicted with doctrines of fundamentalist Protestant Christianity. As Justice Abe Fortas wrote:
There is and can be no doubt that the First Amendment does not permit the State to require that teaching and learning must be tailored to the principles or prohibitions of any religious sect or dogma.
This decision prevented schools from banning evolution in public schools, so creationists sought another way to stop "godless" evolution: "scientific creationism." This was designed to challenge evolution in the science classes without appearing to be religious. Creationists worked for the passage of "balanced treatment" laws mandating the teaching of creation science whenever evolution was taught. Arkansas again took the lead with Act 590 in 1981 mandating "balanced treatment" between evolution and creation science
A number of people, including local clergy, sued under the argument that this law impermissibly caused the government to give special support and consideration to one type of religious doctrine. A federal judge found the law unconstitutional in 1981 and declared creationism to be religious in nature ( McLean v. Arkansas).
Creationists decided not to appeal, pinning their hopes on a Louisiana case they thought they had a better chance of winning. Louisiana had passed a "Creationism Act" preventing evolution from being taught unless biblical creationism accompanied it. Voting 7-2 in Edwards v. Aguillard, the Court invalidated the law as a violation of the Establishment Clause. Justice Brennan wrote:
...the Creationism Act is designed either to promote the theory of creation science which embodies a particular religious tenet by requiring that creation science be taught whenever evolution is taught or to prohibit the teaching of a scientific theory disfavored by certain religious sects by forbidding the teaching of evolution when creation science is not also taught. The Establishment Clause, however, "forbids alike the preference of a religious doctrine or the prohibition of theory which is deemed antagonistic to a particular dogma."Because the primary purpose of the Creationism Act is to advance a particular religious belief, the Act endorses religion in violation of the First Amendment.
Lower Court Decisions
The debates continue in the lower courts. In 1994 the Tangipahoa Parish school district passed a law requiring teachers to read aloud a disclaimer before teaching evolution. The 5th Circuit Court of Appeals found in Freiler v. Tangipahoa that the stated "critical thinking" reasons for the disclaimer were a sham. Even if a valid secular purpose for the disclaimer existed, though, the court also found that the actual effects of the disclaimer were religious because it encouraged students to read and meditate upon religion in general and the "Biblical version of Creation" in particular.
Another creationist tactic was tried by biology teacher John Peloza in 1994. He sued his school district for forcing him to teach the "religion" of "evolutionism." The Ninth Circuit Court of Appeals complete rejected all of Peloza's arguments in Peloza v. Capistrano. They found that his arguments were inconsistent - sometimes he objected to teaching evolutionary theory, sometimes he objected to teaching evolution as a fact — and held that evolution is in no way a religion and has nothing to do with the origins of the universe.
Webster v. New Lenox School District was decided in 1990 by the 7th Circuit Court of Appeals. Ray Webster had been instructed not to teach creation science in his social studies class but he filed suit and claimed that the New Lenox School District violated his first and Fourteenth Amendment rights by prohibiting him from teaching a nonevolutionary theory of creation in the classroom. The court rejected each of his allegations and established that school districts can forbid creationism as a form of religious advocacy.
Creation scientists have failed in their attempts to have evolution legally banned from the classroom or to have creationism taught alongside evolution, but politically active creationists have not given up — nor are they likely to.
Creationists are encouraged to run for local school boards to gain control over science standards, with long-term hopes of diluting and eliminating evolution through slow attrition. This need only happen in a few areas to be successful because some states command a larger share of the market for school text books than others. If the text book publishers cannot easily sell books with a strong emphasis on evolution to large markets like Texas, then they are unlikely to go to bother publishing two versions. It doesn't matter where creationists become successful because. in the long run, they may end up affecting everyone.