"Underdog" is not liberal or a liberal thing or about victimization.
"Underdog" means "underdog." It is not a political stance, a political party, a race, or a synonym for someone who thinks they are a perpetual victim. For example, on September 11, 2001, the United States of America became an underdog. For the first time in nearly two centuries.
On this site, 'Liberals' are in the minority, swamped by a bunch of Trumpers. That would make them the underdog.
On the UK-based Alternative Rock forum I used to visit before here, Americans were a very small minority, and right-wing Americans even smaller still. That would make them the underdog. Over there, I came across quite a bit differently than I do here because of that.
On Pinterest, on Afrocentric Pins, Afrocentrics swamp those who aren't. So those who are not Afrocentrics are the underdog. Yet the Afrocentrics are the ones crying victimization. This while claiming that sub-Saharan Africans started all civilizations throughout the world, and that the original Chinese, Asian Indians, Mesopotamians, Greeks, Etruscans, Vikings, Moors, Medieval European kings, Japanese, Olmecs, Aztecs - in fact all Native Americans were actually sub-Saharan Africans. They're actually telling real life Native Americans there that they are not the actual indigenous Americans, but the descendants of Filipino slaves brought by the Spanish to Mexico and that African slaves were never brought from Africa, that that's actually all a big con because they were the actual indigenous here in the Americas.
Out in the world, Afrocentrics would be an extreme minority. I just realized a couple of weeks ago that I was actually shadowbanned for insulting Afrocentrics as they call me an albino Neanderthal caveman colonialist who is stealing their culture by informing them that ancient Egyptians were Egyptians, not sub-Saharan Africans, as well as setting them straight on all the other peoples whose identities they're trying to pretend are theirs.
They're like the opposite of the DEI hollering MAGAs here. Well, actually they're the same thing. But nevertheless, over there, MAGAs would be the underdog.