Mitt Romney used to talk up the “crucial” importance of having two parents in the home, saying “a mom and dad together” have a big impact. But over the past week, he has been extolling the virtues of single mothers at every turn, holding them out as examples of Americans “living for something bigger than themselves.”

Mr. Romney once delivered partisan-tinged zingers about how President Obama takes inspiration from socialist Democrats in Europe.

There are no traces of such barbs in the dwindling days of the race, however, even as a devastating storm buffeted the campaign and much of the country. Instead, he promises to make frequent and personal outreach to the rival party a signature of a Romney presidency.