WASHINGTON -- An adviser to President Barack Obama's re-election campaign said Sunday that GOP presidential candidate Rick Santorum went "well over the line" when he questioned Obama's Christian values.
Robert Gibbs said on ABC's This Week that it's time "to get rid of this mindset in our politics that, if we disagree, we have to question character and faith."
The country would be better-served, Gibbs said, if presidential candidates focused instead on the economic challenges the middle class faces.
Santorum said Saturday that Obama's agenda is tied to "some phony theology" not based on the Bible.
Obama's campaign team has shifted gears in recent days to consider the possibility that his GOP opponent will be Santorum instead of Mitt Romney.
Campaign officials confirm that Obama's Chicago-based organization has begun combing through the former Pennsylvania senator's background looking for lines of attack. It also e-mailed Obama's Pennsylvania supporters this past week asking for material that could be used against Santorum in speeches and ads.
The move reflects Santorum's sudden surge in nationwide opinion polls and a spate of recent primary-season victories over Romney.