Disclaimer: USA context.
I came across an interesting idea this morning:
Conservatives defend the liberal gains of the past.
A classic example is the American founding. A revolution by liberals whose ideals are, today, defended by conservatives.
A modern example seems to be free speech, which used to be an issue supported by liberals, but has become an issue supported by conservatives, as it has come under attack from liberals.
They say people get more conservative as they get older. I wonder if the people are changing or if the meaning of liberal and conservative change as they age.