Obama leads Romney in most polls, including the most recent Wall Street Journal/NBC News poll released Wednesday, but all signs indicate the two men are running a very tight race.

Somerhalder, best known for his roles on the TV series "Lost" and "The Vampire Diaries," has previously testified about the plight of endangered species before a subcommittee of the House Natural Resources Committee and used his eponymous environmental foundation to petition against the Keystone XL pipeline.