Al Gore, private citizen, continues to do much more to shape the global political debate than Al Gore, senator or vice president.

We are all familiar for his amazing work on climate change. Now Gore, who as vice president supported the Defense of Marriage Act, posted a video on his Current TV Web site in which he stands up for gay marriage:

“Gay men and women ought to have the same rights as heterosexual men and women — to make contracts, to have hospital visiting rights, to join together in marriage … I don’t understand why it is considered by some people to be a threat to heterosexual marriage.”

The Politico notes that this pushes the Democratic establishment toward a position he now shares with some leading Dems, and may prompt grumbling in gay political circles that this batch of candidates aren’t there.

Indeed, all three Democratic contenders support equal rights for gay and lesbian couples, but have sought to woo gay voters indirectly: Elizabeth Edwards has voiced support for same-sex marriage, while Barack Obama recently chastised the black church for its history of homophobia.

Will Al Gore’s comments up the ante?