On the contrary. Democrats have very effective propaganda, er, "messaging". How else do you explain Andrew Cuomo having such a high approval rating with the crisis in his state? How else do you explain the fact that people actually expected the Mueller report to bring down Trump? The dems' talking points are full of hypnotic language, probably forged in focus groups. Many of their positions sound intuitively true and have superficial appeal, such as taxing the wealthy more, banning guns to reduce violence, and providing free college and health care.
It actually requires some effort to see leftists' childish, privileged politics for what they are.