HOUSTON -

A two-day showdown over same-sex marriage began Tuesday in Washington, D.C.

Thousands of supporters and opponents gathered outside the U.S. Supreme Court.

Justices heard arguments on Proposition 8, approved by California voters, that banned gay marriage in that state after courts had previously ruled they were legal.

"These issues have been building over a long period of time," said Reverend Lisa Hunt of St. Stephen's Episcopal Church in Montrose.

Earlier this month, Hunt officiated the church's first-ever blessing ceremony of a same-sex couple in Houston.

"We certainly didn't pick the date of this commitment with an eye toward same-sex marriage Supreme Court argument," said Hunt. "But I think it does speak to the fact that the momentum is moving in our country and in our church."

According to a CNN/ORC Poll conducted March 15 to March 17, 53 percent of Americans are in favor of same-sex marriages.

"It appears that the majority of people now support it and so it's a very difficult case for the court, because they don't want to end up on the wrong side of history," said Aaron Bruhl, Associate Law Professor at the University of Houston.

Those who want to uphold the ban said it protects the traditional idea of marriage and its intent to encourage procreation.

"But in religious life, we also know that marriage provides counsel and joy and perplexity, as well as companionship," said Hunt.

On Wednesday, the court will hear oral arguments on the Defense of Marriage Act. The act defines a federal law that defines marriage as a union between a man and a woman.

Rulings in both cases are expected in June.