The Democrats would be a more liberal party if the electorate were more liberal.
IMO the positions of both parties have drifted right to attract donors, which are unfortunately worth quite a bit more than voters.
This. Since “Citizens United”, it’s getting harder to distinguish when a politician is trying to attract voters, and when they are trying to attract funding. You’re right it’s more usually the latter, since that generally leads to the former (sadly).
Hasn’t it always been practically impossible to tell?
In many cases, yes. But there’s some “They Live glasses”-style giveaways. Like every time Mr. Environmentalist Al Gore said the words “Clean Coal” during the Presidential debates, he was very clearly angling for Energy Sector funding.