Don't let terminology screw up understanding.
Conservative and liberal are basic personality types that WE ARE BORN WITH. They're genetically determined. THEN environment gets involved and is also a powerful force, but it can't completely wipe out inborn traits. Half of all Americans are naturally conservative, cutting across all racial, religious, ethnic and gender types. And they always will be.
So, conservative and liberal are not synonymous with Republican and Democrat, it's just that increasingly cons gather in the GOP and liberals in the Democratic Party.
What is currently effectively "dead" or purged is TRADITIONAL CONSERVATISM as a guiding principle of the Republican Party. Abe Lincoln tried to define that as what he clearly felt was conservatism's great contribution to society. What is conservatism? Is it not the adherence to the old and tried against the new and untried? (He was no fool, he knew there was more to it.)
Traditional conservatism could be purged from the Republican Party over the last 40 years because there is no ingrained cultural tradition of conservatism as a political philosophy, just a knee-jerk response to events that can be harnessed by any bad leader.
(The liberal philosophy that lives in the Democratic Party, by contrast, arose during the Enlightenment, the Age of Reason, and the principles our nation was established on are intrinsically liberal and progressive -- equality, government of, by and for the people, etcetera)
What happened to the GOP is that after WWII conservative thinkers tried to develop what Lincoln expressed into an intellectual ideology for conservatism, and for the Republican Party. But as we see, the GOP was subsequently taken over by wealthy conservatives who have no interest in anything that doesn't increase profits. And with their takeover came the purge of any guiding principles and the mass corruption of Republican voters to their service.
So watch it when claiming conservatism itself is dead or it may roll over you while you watch. People eager to support their leaders' desire to privatize our 240+-year-old USPS (so they can pay $5 to send a card to the nearest group mailboxes to their aunt's house) epitomize the death of conservatism as a Republican principle, but they are conservative and very much alive.