One of the things about the improbable Newt Gingrich surge and the even more improbable chance that he'll win the nomination is that most of the stuff in the fat opposition research file on him has only barely started to go into circulation. I very much doubt whether many rank-and-file Republicans are aware that he was busted (by the House Ethics Committee) on an ethics violation way back when, for example.
But you know what else I don't think people realize about Newt? He's, well, old. Born in 1943. Part of his standard talking points about his marital history stress that he's a grandfather (because...oh, it's just too depressing to focus on). And you know what? Of course he is. He'll turn 69 in June. He wouldn't be a record-breaking first time nominee; that would be Bob Dole (turned 73 in 1996) and John McCain, (72 in 2008). And he'd be a few months younger than Ronald Reagan was in 1980. But still, that's pretty old.
Of course, it helps him that Ron Paul is up on the stage, and he's a lot older (b. 1935). The rest? Prince Herman was born in 1945, Mitt Romney in 1947, Rick Perry in 1950, Gary Johnson in 1953, and then the rest are younger.
I don't really have much to say about this, just though it was overlooked. Both McCain and Reagan took a fair amount of general election heat over their age, but I doubt if it made much of a difference. Then there's the question of electioneering, and whether candidates have the stamina to grind it out over the course of a long campaign. I have no reason to believe that Newt doesn't, but for whatever it's worth the history of older candidates is that the press tends to be quick to jump to speculation about systematic effects of age as soon as an older candidate sneezes. Obviously, however, it's hard to say that it's a disadvantage in the nomination contest. George H.W. Bush was 64 in 1988, and of course George W. Bush was a comparative baby, but Republican voters certainly don't have anything against older candidates. So in the modern era, the two Bushes have so far been the youngest new nominees, and I think everyone would agree that the odds of this cycle's winner topping 60, at least, must be pretty high.