Al Gore's book Earth in the Balance was published in 1992 during his run with Bill Clinton as the VP candidate. Still, that doesn't mean he didn't do a book signing for a reprint in 2000 as a campaign stunt, but I don't know.
His book An Inconvenient Truth was published in 2006, midway through George W. Bush's second term.
The Gores separated in 2010, but never divorced. That doesn't mean that he wasn't taking his ring off in 2000 when Tipper wasn't around, but that sloppy kiss during the 2000 DNC convention was a bit creepy.
-PJ
I don't give Algore a lot of thought; but I'll never forget the sight of that white dent around his finger up close, and then watching him schmooze the girls afterward. That he wasn't formally separated really grossed me out.