President Bush won Colorado in 2000 and 2004, but Democrats hope to swing the state this year. Candidates will have to meet voter concerns about energy and the environment.
The battle for electoral votes will be fought in high unemployment states such as Michigan, but also in places with relatively low unemployment such as Virginia.
Tropical Storm Fay continued its erratic path, moving north along the Florida coast but not going out over the Atlantic Ocean, where many had feared it could strengthen and turn into a hurricane.
U.S. Secretary of State Condoleezza Rice and Polish Foreign Minister Radek Sikorski have signed a deal that will put an American missile defense base in Poland, a move that has angered Russia.
Day 12 highlights: Both the U.S. men's beach volleyball and women's softball teams will be moving on to the finals to play for gold medals.
Barack Obama's newly minted running mate will be hitting the trail with the Democratic hopeful Saturday, a senior Obama adviser told The Associated Press on Tuesday.
LeRoi Moore, sax player and founding member of the Dave Matthews Band, has died at age 46. He was seriously injured in an ATV accident in June.
Hua Guofeng, who briefly ruled China as Mao Zedong's handpicked successor before being toppled by reformists, died Wednesday. He was 87.