HARRIMAN, Tenn. (AP) — Republican presidential hopeful Herman Cain says he's challenging Gov. Rick Perry for the GOP primary's critical evangelical vote.In an interview with The Associated Press on Saturday, Cain said the Texas governor "thought he had carved out that niche when he didn't own that niche by himself."The Georgia businessman said he doesn't wear his Christian faith "on my forehead" but believes his campaign will do well with religious conservative voters.Cain drew rousing applause at a recent Values Voters Summit. Perry has a strong track record among religious, voters organizing a rally just before entering the race for the White House that race that drew 30,000 people.Cain was barnstorming across Tennessee Saturday completing a bus tour. Polls show him vaulting to the top tier of the GOP contest.