John Tyler, who died in 1862, wasn't a true Whig. He was a Democrat who broke with the party over factional differences. He thought Andrew Jackson too high-handed and autocratic. Tyler thought that Jackson used extraconstitutional actions against the national bank, but he also didn't like Jackson's firm stance against South Carolina's nullifiers. As president, Tyler governed more as a Democrat than as a Whig, and most of the cabinet he inherited from Harrison resigned early on. Alexander Stephens had been a Whig and a friend of Abraham Lincoln, but Tyler was a Democrat at heart and committed to slavery and the Democrat's idea of state's rights.
I like how you decide who “wasn’t a true Whig” or “was a Democrat at heart”. Clears up any untidy rubble that might interfere with the authorized version. I expect History By Seance to arrive soon, to better confirm those judgments.