Rick Santorum on Tuesday released a new ad that describes Mitt Romney as “just like” President Barack Obama on gay rights.

In the 30-second ad titled Easy Answer, a male announcer says: “Obama is a liberal on social issues. Romney once bragged that he's even more liberal than [Senator] Ted Kennedy on social issues.”

“Why would we ever vote for someone who is just like Obama?” the announcer rhetorically asks. “When we can unite around Rick Santorum and beat Obama.” (The video is embedded in the right panel of this page. Visit our video library for more videos.)

The ad's reference to the late Kennedy is valid. During his 1994 campaign to unseat Democrat Kennedy, Romney promised gay GOP group Log Cabin Republicans that if elected he would do more for “full equality” for gay men and lesbians than his opponent.

Romney has defended himself by saying that he was not endorsing gay marriage.

“What happened was that the gay community changed their perspective as to what they wanted,” Romney told Piers Morgan on his CNN talk show Piers Morgan Tonight.

“I oppose same-sex marriage,” he said. “At the same time, I would advance the efforts not to discriminate against people who are gay.”