Down to the Wire
In 36 of the last 47 cycles since 1828, the margin of victory in presidential elections has been less than one percentage point in at least one state. [And less than one-tenth of a percentage point in a dozen of these cycles]. Twenty-eight states hold the distinction of hosting the closest race over this 47-cycle stretch, with Kentucky leading the way with five (1896, 1900, 1920, 1952, 1996). California (1868, 1880, 1892, 1912), Maryland (1828, 1832, 1872, 1904), and Missouri (1908, 1956, 1968, 2008) have each hosted the tightest race in four cycles. In only three cycles has the closest statewide race been decided by more than 1.75 points: Louisiana in 1856 (James Buchanan over Millard Fillmore by 3.39 points), North Dakota in 1924 (Calvin Coolidge over Robert LaFollette by 2.52 points), and 1972 (Richard Nixon over George McGovern by 5.51 points).
great post