In the final weeks of the campaign, American movie theaters agreed to play two short newsreel-like campaign films in support of the two major-party candidates: both had been created by its respective campaign organization. The Dewey film, shot professionally on an impressive budget, featured very high production values but somehow reinforced an image of the New York governor as cautious and distant. On the other hand, the Truman film, hastily assembled on virtually no budget by the perpetually cash-short Truman campaign, relied heavily on public-domain and newsreel footage of the president taking part in major world events and signing important legislation. Perhaps unintentionally, the Truman film visually reinforced an image of him as engaged and decisive. Years later, historian David McCullough cited the expensive but lackluster Dewey film and the far cheaper but more effective Truman film as important factors in determining the preferences of undecided voters. As the campaign drew to a close, the polls showed Truman was gaining: though Truman lost all nine of the Gallup Poll's post-convention surveys, Dewey's Gallup lead dropped from 17 points in late September to nine points in mid-October and just five points by the end of the month, just above the poll's margin of error. Although Truman was gaining momentum, most political analysts were reluctant to break with the conventional wisdom and say that a Truman victory was a serious possibility. After 1948, pollsters would constantly test voters through election day.