Republican presidential candidate Mitt Romney is starting to open up a bit more about his lifelong commitment to Mormonism.

He invited reporters to Mormon chapel services with his family. And he has asked a fellow Mormon to give an invocation before he speaks at the Republican National Convention next week. He recently rolled out an ad on religious values, although he didn't identify himself as Mormon.

Backers have been arguing that Romney should talk more about his religious beliefs. They say it could help overcome his struggles to connect with voters.

Romney is the first Mormon presidential nominee of a major political party. But highlighting his faith carries risks. Americans know little about Mormonism, and what they do know often comes from critics.