It died out when principle became a bad word and called 'the problem' by leftists infiltrating the ranks with the express purpose of destroying conservatism.
Today we see people claiming to be conservatives pushing for giving Planned Parenthood money, calling for economic slavery to the blessed homosexual of Christian businesses and myriad excuses of why Sharia should be imported to America unfettered.
Conservatism died because 'conservatives' killed it through their own apathy. They could not be assed to purge liberalism from their ranks, it got a toe hold, spread and metastasized.