Why do liberals lie and say that the Cuban trade embargo hasn't worked when it has?

We don't have competition from Cuban rum, we don't lose tourists to Cuba, we don't have a competing sugar supplier, we have never been invaded by Cuba and now it's unlikely that we will, but if we were to lift the embargo that could empower Cuba and enable them to launch an invasion. Face it, the embargo is working and we are not being threatened by Cuba as a result. We also send out a strong message to the rest of the world: we do not do business with communists and we do not recognize dictators. If it takes another fifty years and the starvation of every Cuban man, woman and child, it will be worth it. If you know of any American who has illegally visited Cuba or bought Cuban products while abroad, you can receive a reward for informing law-enforcement authorities.