What did Al Gore do wrong in 2000 election to lose it?

I am not talking about recount in Florida. IMHO, it should have never gone there. USA was coming off with an incredibly strong economy (thanks to dotcom bubble), Clinton was still very popular. By all convention wisdom, Al Gore should have won it in a slam dunk, but he did NOT! He didn't even win his home state of Tennesse. What gives? What did he do wrong?