Republican presidential candidate Mitt Romney, who trails former House Speaker Newt Gingrich by double digits in key early states, told The Washington Examiner on Wednesday that he believes he can still clinch the nomination by winning contests later in the primary calendar and by waiting for Gingrich’s newfound popularity to fade. In a wide-ranging interview with The Examiner’s editorial board, the former Massachusetts governor said he couldn’t explain why his poll numbers have remained stagnant while a succession of other GOP candidates have surged ahead of him. But he predicts Gingrich, the latest to supercede him in the polls, will...