Al and Tipper Gore

Former U.S. Vice President Al Gore and wife Tipper Gore attend the 79th Annual Academy Awards held at the Kodak Theatre on Feb. 25, 2007, in Hollywood, Calif.

Former Vice President Al Gore and his wife, Tipper, arrive to the Entertainment Weekly Party at the Sundance Film Festival Saturday, Jan. 21, 2006, in Park City, Utah.

Former Vice president Al Gore and wife Tipper Gore arrive at the 59th Annual Primetime Emmy Awards at the Shrine Auditorium on Sept. 16, 2007, in Los Angeles.

From left, Tipper Gore, singer Jon Bon Jovi, his wife, Dorothea Hurley, and former Vice President Al Gore attend the opening night after party for "SOS" at the 2007 Tribeca Film Festival on April 25, 2007, in New York.

Al and Tipper Gore enjoy the group Earth, Wind and Fire at the Nobel Peace Prize Concert in Oslo, Tuesday, Dec. 11, 2007.

Former Vice President Al Gore kisses his wife, Tipper, after addressing the delegates during the Democratic National Convention at the FleetCenter in Boston on July 26, 2004.

Former Vice President Al Gore and his wife, Tipper ,arrive at Washington National Cathedral to attend the funeral service for former President Ronald Reagan, Friday, June 11, 2004.

Bill and Hillary Clinton share a light moment with vice presidential candidate Al Gore and his wife Tipper, during a brief rest on their bus in Durham, N.C., prior to the 1996 elections.

Former Vice President Al Gore, left, and his wife, Tipper Gore, arrive for the screening of the film "Selon Charlie," at the 59th International film festival in Cannes, southern France, on Saturday, May 20, 2006.

Former Vice President, Al Gore, poses with his wife, Tipper, as they arrive at the premiere of his documentary "An Inconvenient Truth" in Los Angeles, Tuesday, May 16, 2006.

%7B8FAgore-2.jpg — AP Photo/Stephen Savoia, File

Then-Vice President Al Gore kisses his wife, Tipper, as he steps onto the stage at the Democratic National Convention in Los Angeles on Aug. 17, 2000.

Former U.S. Vice President Al Gore, daughter Kristin Gore, and wife, Tipper Gore, attend Warner Music Group's 2007 Grammy Party held at The Cathedral on Feb. 11, 2007, in Los Angeles.

Al Gore, former vice president of the United States, right, and his wife, Tipper Gore, pose for photographers as they arrive for the premiere of the film "The Three Burials of Melquiades Estrada" Monday, Dec. 12, 2005, in New York. The film stars Tommy Lee Jones and was directed by Jones, who went to school with Mr. Gore.

From left to right: Al Gore, Tipper Gore, actress Meryl Streep, Prince Charles and director of the Center for Health and the Global Environment at Harvard Medical School, Dr. Eric Chivian meet during the 10th Global Environmental Citizen Awards ceremony in New York, Jan. 28, 2007.

Former U.S Vice President Al Gore, second from right, and his wife, Tipper Gore, second from left, with producers Lawrence Bender, left, and Laurie David arrive for the screening for the film "An Inconvenient Truth," at the 59th International film festival in Cannes, France, on Saturday, May 20, 2006.

Spain's Prince Felipe and Princess Letizia Ortiz, second left, welcome former Vice President and 2007 Nobel Peace Prize winner Al Gore and his wife, Tipper, in Oviedo, Spain, Friday, Oct. 26, 2007, before the ceremony of the year's prestigious Prince of Asturias prizes. Gore received the 2007 Prince of Asturias Award for International Cooperation.

Nobel Peace Prize laureate Al Gore, second left, and his wife Tipper, left, meet Norway's King Harald, second right, and Queen Sonja in the Royal Palace in Oslo Monday, Dec. 10, 2007.

Then-Democratic presidential candidate Vice President Al Gore gets a kiss from his wife, Tipper, during a campaign rally at the University of Michigan in Dearborn, Mich., on Nov. 5, 2000.