Employers pay what they have to attract and keep the workers they need. When taxes go down, employers realize they can pay that much less and still get the labor they need because take-home pay will be the same as before. Tax cuts then end up benefiting capital, not labor. Actually, they usually harm labor because often force reductions in government spending for programs that benefit workers. By forcing millions of people into the labor market to compete for jobs, wages will fall even further, and workers currently employed will lose their jobs to welfare job-seekers.
Capitalism is a lose-lose situation for the working class.
The tax issue is just a giant smoke screen designed to fool workers into believing that the reason they can't make ends meet is because their taxes are too high. As the global economy greatly increases the supply of labor, automation keeps decreasing the demand for it by eliminating jobs. So wages keep going down, down, down. This may keep the capitalists jumping for joy today, but as the system methodically undermines its mass consumer market, it plods blindly yet inexorably to ultimate collapse. All of which makes the election campaign so much sound and fury, signifying nothing.