Many etymologies have been proposed for the term "O.K." or okay, but none have been unanimously agreed upon. One of the etymologies is linked ot the city of Kinderhook. President Van Buren was called "the Wizard of Kinderhook" and "Old Kinderhook". To turn this into an advantage for his elections, the democrats spinned the term and called it "The Democratic O.K. club" where O.K. stands for "Old Kinderhook". It became a very popular slogan. Nevertheless, president Van Buren lost the elections in 1840 (William Henry Harrison won). But still, if this theory about the origin of "O.K." is true, he did get out something out of these elections.
Source: Ewoud Sanders, Geoniemen Woordenboek