The left convinces people to vote for them by catering to your feelings. It sounds good to take from the rich and give to the needy. It feels good to give stuff to people. It feels good save the animals by telling people not to eat meat. People feel like their doing something good.
They also useguilt. They guilt you into accepting their way of thinking. They guilt you into believing global warming. They guilt you into voting to raise your own taxes, "You have so much, and the poor have so little." They guilt you into approving their tax hikes on the people who create jobs: "They are greedy rich people." They guilt you into supporting their regulations on those who create jobs: "They are polluting your air without these regulations."