Republican lawmakers continue to pressure the White House for answers over the attack on the U.S. consulate in Libya that killed four Americans, including U.S. Ambassador Chris Stevens.

The Obama administration blames its shifting story on intelligence information, saying it changed as the evidence changed.

"And there is no doubt, some of these matters went into the security department at the state security agency at the State Department. But it didn't come to the White House and that is what the vice president was responding to," David Axelrod, senior Obama campaign strategist, said on "Fox News Sunday."

But Republicans aren't buying that explanation.

"There were no riots at all. So to say that, you're either very incompetent or you're misleading," Sen. Lindsey Graham, R-S.C., said on CBS "Face the Nation" Sunday.

"The intelligence community on the ground in Libya has told Sen. Corker and myself that within 24 hours, they communicated up to Washington that this was a terrorist attack," he continued. "The president of Libya, on the same day, said it was a terrorist attack."

Democrats accuse Republicans of turning the death of Ambassador Stevens into a campaign issue.

But Sen. Rob Portman told ABC News that it's not a campaign issue, it's simply an issue.