PHOENIX — GOP presidential candidate Rick Santorum is making increasingly harsh remarks about President Barack Obama. He questions not only Obama's competence but also his motives and even his Christian values.

Santorum says Obama cares only about power, not the "interests of people." He says the president's health care overhaul includes a "hidden message" about the president's disregard for impaired fetuses, which might be aborted.

Santorum even seemed to compare Obama to Adolf Hitler, although he denied trying to do so.

Santorum's remarks contrast with those of Mitt Romney. Romney generally says Obama is decent but inept.

Newt Gingrich also challenges Obama's motives. He called Obama the most dangerous president in modern U.S. history.