Well, the time for the endorsement everyone has been waiting for has finally arrived: Former Vice President Al Gore will endorse Barack Obama tonight.

Gore made the announcement on his blog and in an e-mail to supporters on Monday afternoon. "A few hours from now I will step on stage in Detroit, Michigan to announce my support for Senator Barack Obama. From now through Election Day, I intend to do whatever I can to make sure he is elected President of the United States," Gore wrote. "I've never asked members of AlGore.com to contribute to a political campaign before, but this moment and this election are too important to let pass without taking action.

"That's why I am asking you to join me today in showing your support for Barack Obama by making a contribution to his campaign today."

Gore and Obama will appear together at the event, which will be held in Detroit's Joe Louis Arena. The two are expected to be onstage at about 8:30 EDT.

This isn't the first big endorsement event Obama has held in Michigan. Just over a month ago, former Sen. John Edwards announced his support for Obama during a rally in Grand Rapids.