Mitt Romney Steps Up Attacks On Newt Gingrich

Both in advertising:

And in stump-speech rhetoric. Romney, in Florida:
So I've had the experience of leadership. Now Speaker Gingrich has also been a leader. He was a leader for four years as speaker of the House. And at the end of four years it was proven he was a failed leader. And he had to resign in disgrace. I don't know if you knew that. He actually resigned after four years in disgrace. He was investigated under an ethics panel and had to make a payment associated with that and then his fellow Republicans, 88 percent of Republicans, voted to reprimand Speaker Gingrich. He has not had a record of successful leadership.
This is quite a large deviation from Romney's strategy. Heretofore, Romney has been focusing nearly all of his criticism on President Obama -- staying above the fray, as it were -- but now it seems that his campaign is adopting a different tack.