Lexicus
Deity
I find this distinction only sometimes is helpful and usually is the opposite.
There's always levels. At the level of any kind of critique of political economy the distinction does start to matter because what distinguishes liberals is they don't really have critiques of today's political economy, or if they do they are essentially toothless and/or incoherent (Liz Warren's "break up the banks" being a typical example).
And before you were born, was steadily decreasing. There was a huge change after you were born, and it was instigated by one party.
As to this, I think it kinda depends what level you're talking about. On the most basic level, Democrats briefly had the New Deal coalition which was all about decreasing inequality and voted effectively for policies that succeeded in doing that. Now, I think it is actually primarily the World War II mobilization and not the New Deal that took us from the very unequal 1920s and 30s to the relatively equal 50s and 60s, but regardless, having the New Deal Coalition in power at that time was crucial to ensure broad-based sharing in the economic gainz. All this time the Republicans were trying to undo this, the Old Money faction of the GOP resigned itself to the New Deal in the 50s (e.g. Eisenhower writing that those who wanted to get rid of social security were a small number of idiots) but the mostly Western new money always bitterly hated it (and its corollary/continuation in the expansion of black participation in mainstream society).
The thing is, while Republicans have been trying, comprehensively and constantly, to increase inequality (racial and economic) since at least the 1970s, the Democrats are the ones who are supposed to be for more equality, so when the Democrats have lapses on this, it hits different than when Republicans are just being Republicans. I blame Bill Clinton more bitterly for financial deregulation than Reagan, because Reagan was what he was, and more importantly I don't have to listen to Democrats telling me Ronald Reagan actually did nothing wrong. We have higher expectations of the Democrats, and so when they are corrupt and engage in stupid neoliberal garbage we are more disappointed than when Republicans do even worse things, because we expect nothing but savagery from Republicans anyway.