Conservatism is all but dead in today's Republican Party which is radical extremism.
There was at one time a cautionary approach to economics based on a rational idea,
you can spend too much money on the wrong things. That has been thrown out the window with the rise of the M.I.C. (Military Industrial Complex), Libertarianism, Paul Ryan and the Religious Wrong. Ronald Reagan and Barry Goldwater would have a tough time today. Military expansionism might be a true conservative view as well as re-instituting tariffs to protect American workers (something that I as a Lefty would advocate).

Teddy Roosevelt was a conservative on the issue of environmental abuse. Oddly, he would be closer today to Al Gore.