Taylor's ideas of what to do with the Mexican Cession were uniquely his own and never gained traction. Had he lived, he wouldn't have been renominated, let alone reelected in 1852 and that election would have fought over the issue of what to do with the Mexican Cession. That would likely have split apart the Whig Party as happened in real life.
The Whigs routinely got themselves into trouble because their Presidents/nominees were picked bc of their personal popularity and not adherence to their political principles. Considering how divided the party was this was probably their only real option though.
