Yes, that’s broadly right. The number of principled ideologues is always very low compared to those who see that an ideology has something for them and then follow it. I’m not suggesting these people are self-aware hypocrites that’s just how human psychology works.
In under a generation people go from arguing that everyone deserves equal rights and dignity to campaigning for explicit racial privileges for their side, or from supporting the right of the federal government to seize slaves who escape and travel to a free state to yakking about state’s rights to justify Jim Crow, or the one we’re in the trailing end of right now, the transition from free speech being a left wing value to a right wing one. When the right had the establishment the left was all about people’s right to speak and be heard. Now that they’re in charge it’s safe spaces and hate speech. Or look at the collapse of the anti-war movement once Obama was elected. Bush bombed Muslims for eight years, Obama bombed Muslims for eight years. Bush destroyed Iraq and had no real effect in Afghanistan as it comes pre destroyed. Obama destroyer Libya and cape quite close with Syria before his good sense overcame the presence of Hilary Clinton in his cabinet.
Politics is overwhelmingly about sides, coalitions and spoils. Insofar as it’s about ideology most people have 1-3 things they really care about and the rest they’re pretty happy to modify to fit in with their coalition.