Parties in the US aren't real, though the brand value is good at keeping the right kind of people in each one. They can't actually kick anyone out and people in the federal government have no particular control over same party people in any state.

From my view, the two parties are quite a bit more real than the 3 branches of government. The people funding state and federal elections are the same.

If you mean campaign funding, that's mostly Actblue (upper middle class Dem donors). Republican donors are like, five people, yes - but voters have their own opinions and they definitely don't vote for whoever has the most money. Because the Democrats have more of it.