Should she win the White House in next year's election, Democratic presidential bet Hillary Clinton vowed that she would do everything in her power to promote gay rights.

This was a stark turnaround from someone who—more than two decades ago when she was still the First Lady, then a senator, and then a presidential candidate—used to be a staunch opponent of same-sex marriage, according to Fox News.

Even early this year, Clinton said while she personally supported same-sex union, the subject was best left for states to decide, not the President's—which is the position held by most of the Republican presidential candidates, Fox News said.

Speaking at the Human Rights Campaign headquarters in Washington last Saturday, Clinton warned that a vote for Dr. Ben Carson or any other Republican candidate would place fundamental human rights at risk.

"We're going to face some ridiculousness especially from our friends in the GOP. In fact it's already begun. Ben Carson says that marriage equality is what caused the fall of the Roman Empire," she said.

Texas Senator Ted Cruz, on the other hand, "slammed a political opponent for marching in a (gay) pride parade."

"He clearly has no idea what he's missing," Clinton laughingly said. "If any one of them, heaven forbid, were ever to be elected president, they will do their best to threaten you and their families. Every single Republican candidate for president is against marriage equality. Every one of them. Many of them are against anti-discrimination laws. Many are against same sex couples adopting."

After making that announcement, Clinton began to highlight equal rights in her campaign. She promised to pass federal legislation ending discrimination, promote lower costs for HIV treatment, cut off funding for child welfare agencies that discriminate against gay parents, as well as open up military service to transgender people.

Clinton said she was "just getting warmed up" in her battle for equal rights.