On the heels of the slimmest Iowa caucus victory in history, Mitt Romney’s 16-point win in last night's New Hampshire Republican primary was the second-largest margin of victory for a non-incumbent in more than 30 years. In 1980, Ronald Reagan beat George H.W. Bush by nearly 27 points. Back then, Reagan captured just less than 50% of the vote compared with Bush’s 22.7%.
And in 2000, John McCain bested George W. Bush by more than 18 percentage points.
Romney’s win last night also was better than average. Since 1972, non-incumbent New Hampshire victors have won by an average of about 12 percentage points. But the high margin of victory could be due to an usually high diffusion of the remaining vote between the other candidates. Non-incumbent winners received, on average, slightly under 40 percent of the total vote, nearly identical to Romney’s share Tuesday night.
*** Note *** A earlier version of this story noted that Romney's win was the largest margin since Reagan. As it turns out, McCain got an 18-point win in New Hampshire in 2000. So Romney's is the second largest.