Its not one source, its multiple sources.
Conservatives move through the world as it is and how it actually needs to be.
Liberals/leftists move through the world as they would like it to be, but it can never be as they want it because what they want sounds great on paper, but once you throw humans into the mix, their utopian ideas turn to shit. Unfortunately there is a lot of people that passively want what liberals want. They want this nirvana like world where everyone loves everyone and everything is free and no matter how fucked up someone is, even when it is completely their fault, everyone should pitch in to make sure that all are taken care of and welcome, regardless of how dangerous they may be to the whole or unproductive they are. Those people tend to be kids/students. Hollywood is a tool to push that narrative as well, as Hollywood is filled with people who's entire existence is fantasy, and also people who live of their fucked up perspective