In 2009, the Supreme Court of Iowa was asked a question: how can a state premised on the Constitutional principle of equal protection justify exclusion of a class of Iowans from civil marriage?

The decision was that this state could not.

Last week, the U.S. Supreme Court decided that it would also face a similar choice, and though many distracting arguments will be presented, the Supreme Court must decide in favor of equality for Americans.

“ ‘What does it mean to be equal?’ That is what is before the Supreme Court today,” said Linda Kerber, a professor emeritus of history at the University of Iowa. “That is really something you need to cling to, because otherwise you get into distraction.”

Kerber contributed to the amicus brief, or “friend of the court” document, that was presented to the Iowa Supreme Court in 2009. She is again contributing to a brief that will be submitted to the U.S. Supreme Court as it considers some of the arguments for and against same-sex marriage.

In her research, she found that among the many distractions to the basic argument of equality are the arguments that same-sex couples are inadequate at raising children and that traditional marriage must be protected.

The first argument was presented to the state of Iowa Supreme Court, which found: “Many leading organizations, including the American Academy of Pediatrics, the American Psychiatric Association, the American Psychological Association, the National Association of Social Workers, and the Child Welfare League of America, weighed the available research and supported the conclusion that gay and lesbian parents are as effective as heterosexual parents in raising children.”

“If you look at the impact of laws, we filtered a lot of privileges through marriage,” Kerber said. “You get a lot of your coverage through marriage, and once it became practice to allow gay people to adopt, we have children who are not getting equal protection because their parents couldn’t collect rights from the state.”

Denial of the right to marry is a denial of equal protection of the laws, but the first argument is entirely disproved by researchers in many fields. However, the second argument is the basis for the Defense of Marriage Act, which will come under scrutiny by the Supreme Court.

“People who support the Defense of Marriage Act are certain that the definition of marriage has not changed over time,” Kerber said. “But traditional marriage turns out to have many traditions — it is much less stable than you might think.”

Kerber said that over centuries, the definition of marriage changed from allowing women no rights, under the legal principle of coverture to allowing some rights to now having equality.

“There was a time in the revolution of marriage in which there was no concept of rape in marriage,” Kerber said. “I say to people that you may not be a feminist, but would you at least be grateful for them for changing that?”

Not only did the definition of marriage change for women, it also changed for biracial couples.

“Miscegenation made it illegal for a white person to enter into marriage with someone from a different race until Loving v. Virginia in 1967,” Kerber said. “People used to think biracial marriage was shocking and terrible, and now we say it is shocking and terrible that people thought it was shocking and terrible.”

The definition of marriage is a fluid definition in the United States, and the Defense of Marriage Act specifically denies some Americans equal protection under the law.

Whatever objections some may have to same-sex couples, Americans must look past the biased and unfounded distractions and demand equal protection for all people.