ATLANTA – Newt Gingrich on Wednesday brushed aside continuing upheaval in his presidential campaign, noting that Republican hero Ronald Reagan suffered defections in his 1980 campaign and went on to win the White House.

"The fact is, campaigns go up and down," the former House speaker said in a speech before the Atlanta Press Club.

"I'm not running to talk about the nuances of the campaign," he said. "I'm running because we have enormous problems."