But here's the trap for Democrats. There are only three legitimate objectives for a real campaign ad:
1. Turning out your own sporadically-voting leaners.
2. Persuading undecideds and weak supporters of the other guy to vote for you.
3. Getting people to give you money.
If you're really running ahead, a fourth legit use is specifically helping the down-ballot races.
Running ads that stimulate the lizard brains of committed supporters who are already giving you money and prepared to brave a zombie apocalypse to vote for you.
If you use donor money for that, you are wasting it.
Now I'm not saying that the Democratic consultantocracy is always good at making the kinds of ads that move those people. They often aren't.
But some of them are quite good.
But they are not going to move many votes.