If former House Speaker Newt Gingrich manages to win the Republican presidential nomination, he could jeopardize his party’s chances of ousting President Obama next November, according to several new national polls released this week. Surveys from the NBC News and the Wall Street Journal, AP/GfK and Reuters/Ipsos all show former Massachusetts governor Mitt Romney running better than Gingrich in general election matchups against Obama. “Electability will come into play for many Republican votes,” said one neutral GOP consultant who preferred to speak anonymously. “It’s going to become problematic. I think you’re starting to signs of it.” The NBC/WSJ and AP/GfK...