Do people still believe that supply side economics works?

Isn't it merely rich people telling workers that if rich people get paid first workers will eventually prosper? Invariably, the rich do well, garnering a bigger percentage of overall wealth, while the percentage to workers goes down. It does this whenever there is a Republican president. Since wealth is only relative to ones percentage of the pie, why do lower and middle cl Americans still believe this. Aren't they tired of being rich America's fools?