Via political scientist Seth Masket comes this chart showing the distribution of endorsements among the Republican presidential candidates:
Yes, it's true that there haven't been many former candidates, which distorts the graph a little. Even still, it remains the case that while Gingrich might be popular among Republican voters, party elites are far more amenable to Mitt Romney's candidacy. The latest Political Insiders poll from National Journal shows a similar result - only 17 percent of Republican elites (out of 102 surveyed) believed that Gingrich could beat President Obama in a general election. If it's truly the party that decides the nomination, then I have a hard time believing that Gingrich stands a chance, even with his impressive poll numbers.
Of course, it's also true that party elites are competing for influence with conservative media personalities and their outsized influence in Republican politics. Sure, GOP elites might not like Newt Gingrich, but if Rush Limbaugh and Fox News jumps on his bandwagon, will that even matter?