Gallup's Frank Newport posted a memo online defending the organization's 2012 polling, which gave Mitt Romney the lead in the presidential race from mid-October to the end of the month. 

Newport notes that the final pre-election Gallup poll, taken from Nov. 1 to Nov. 4 after a hiatus due to Hurricane Sandy, showed a dead heat, not so far off the final popular vote results. It was a steep drop for Romney from the previous weekly average. 

"In the end, Gallup's national popular vote estimate was that the popular vote was too close to call, a statistical tie -- 50% for Mitt Romney, 49% for Barack Obama," Newport wrote. "When the dust settled, Romney got 48% of the popular vote and Obama received 50%, meaning that Gallup’s percentage-point estimate was within two percentage points for Romney and within one point for Obama." (Further counting has boosted Obama's total closer to 51 percent.) 

However, he added, "it is clear that voting today is subject to new pushes and pulls" and that changes to the pollsters' likely voting model might be necessary. 

Newport also takes what appears to be a veiled shot at The New York Times's Nate Silver, who argued that a mid-October Gallup poll showing Romney ahead -- in contrast to other surveys -- was likely wrong.

"It’s not easy nor cheap to conduct traditional random sample polls," Newport writes. "It’s much easier, cheaper, and mostly less risky to focus on aggregating and analyzing others’ polls." 

A Fordham University study ranking the most accurate election pollsters listed Gallup 24th out of 28 pollsters. 

Republican polling firm Public Opinion Strategies, where the Romney campaign pollster is employed, similarly posted an explanation of its methods.