I read it as “we are aware that these two ideologies are different and frankly they are both such absolute garbage that we don’t really care to distinguish them all that much.”

It’s to show that there is literacy and understanding of nuance there, but that at the end of the day it’s more of a “fun fact” when the centrists keep supporting the conservatives as their general default. Even when Liberals do nothing is about how that nothing is consistently helping the far-right get away with shit while aggressively discouraging progressive change.

Conservatives are nationalist morons who are trying to conserve and bring back a lot of the systems that let low-quality privileged people in their given society keep all the power. Liberals don’t have hating minorites as a policy goal but they also refuse to believe that doing nothing will not, in fact, make up for hundreds of years of systemic issues. Conservatives will try to fix capitalism by ethnic minorities and Liberals will try to fix by getting rid of rules which “might stifle economic expansion”. Neither of those ideologies are worth anything though they are different.