I have my doubts that liberalism will ever be as effective of a motivator as socialism, fascism or religion. Nobody will kill and die for LGBT BBQ rights. On the other hand how many people were willing to kill and be killed for say... Islam?The US wasn’t liberal 60 years ago. Liberalism is a more recent development due to the US losing the initial ideological Cold War to the USSR. Liberalism was basically born during the Civil Rights movement, before then it was a rather blatant form of white supremacism and that was not attractive to anyone outside the West, hence the popularity of Communism through most of the fifties and sixties.
The most primal human driving forces are community, nationalism and religion because they shape our everyday. Liberalism explicitly rejects community and nationalism while trying to replace traditional religions which inspire awe, art and literature with something that people naturally will think is ugly, but aren't allowed to say is ugly.