No, it's not against the law. Because people in this country have the freedom to live any lifestyle they choose, provided they aren't infringing upon the rights of others in doing so.
I think it IS required to have birth certificates, however. THat's where the FLDS folks will end up getting into trouble, I think. Though it's still not something which would ordinarily result in the removal of children.
http://www.usatoday.com/news/opinion/columnist/2004-10-03-turley_x.htm
The difference between a polygamist and the follower of an "alternative lifestyle" is often religion. In addition to protecting privacy, the Constitution is supposed to protect the free exercise of religion unless the religious practice injures a third party or causes some public danger.
However, in its 1878 opinion in Reynolds vs. United States, the court refused to recognize polygamy as a legitimate religious practice, dismissing it in racist and anti-Mormon terms as "almost exclusively a feature of the life of Asiatic and African people." In later decisions, the court declared polygamy to be "a blot on our civilization" and compared it to human sacrifice and "a return to barbarism." Most tellingly, the court found that the practice is "contrary to the spirit of Christianity and of the civilization which Christianity has produced in the Western World."
Contrary to the court's statements, the practice of polygamy is actually one of the common threads between Christians, Jews and Muslims.....
While the justifications have changed over the years, the most common argument today in favor of a criminal ban is that underage girls have been coerced into polygamist marriages. There are indeed such cases. However, banning polygamy is no more a solution to child abuse than banning marriage would be a solution to spousal abuse. The country has laws to punish pedophiles and there is no religious exception to those laws...
While the justifications have changed over the years, the most common argument today in favor of a criminal ban is that underage girls have been coerced into polygamist marriages. There are indeed such cases. However, banning polygamy is no more a solution to child abuse than banning marriage would be a solution to spousal abuse. The country has laws to punish pedophiles and there is no religious exception to those laws.
Jonathan Turley is the Shapiro Professor of Public Interest Law at George Washington Law School.
And how old does a girl have to be to get married with her parents' consent in Texas? I don't think it's very old.