What is a supposed connection between the 8th U.S. President Martin Van Buren and the idiom "OK"?

In 1839 the educated youth of the country enjoyed abbreviations (i.e. lol) much like we do today. Their abbreviations had an extra level though. They would take a misspelled word and turn it into an abbreviation. So no go would be translated into know go and abbreviated as KG.

So on to the birth of the abbreviation OK in the Boston Morning Post. The word origin was All Correct...which instead of being AC it was turned into OK. This post was in reference to Van Buren being "all correct" and it appeared a few more times in the paper and gained widespread popularity.

Now fast forward one year to Van Buren's reelection campaign. The president was from the town of Kinderhook New York and his supporters used the new expression OK as a slogan for Van Buren as Old Kinderhook. Meanwhile, Harrison's supporters were smoking Van Buren as being an Andrew Jackson henchman. Since Jackson was a terrible speller they said that old Andy would spell all correct as ole kurrek!

https://www.history.com/news/the-birth-of-ok-175-years-ago