Do tax cuts really create jobs?

Conservatives say that if the wealthy and corporations gain access to more capital through tax cuts, they will be inclined to hire more people. Corporations have made 88% of the gross national income in the past 1.5 years, while aggregate wages and salaries account for slightly more than 1%. Corporations have posted enormous profits as well, yet they continue to lay off more employees. Is this proof that access to more capital does not actually create jobs? Why don't we realize that it is actually public demand for goods and services that will create jobs in this economy? The "job creators" will only start hiring if normal Americans feel comfortable with buying goods and services again. Therefore, isn't the government the only entity capable of creating jobs through infrastructure programs, and investment into new markets such as renewables, in this slow growing economy? We experienced over a quarter million job losses in the construction sector, if they were able to get back to work through an infrastructure bank, would this stimulate the economy in a positive way? Please don't bother bringing up the debt debate, crumbling infrastructure is a public debt. We will have to pay for it some day, why not do it while construction materials are cheap, and labor is plentiful? It won't matter how much government spending is cut if the economy does not improve, we will continue accruing debt if our economy remains as is. Why not create programs for the middle cl that will make them prosperous, instead of tax cuts for the wealthy that will only be used for bonuses?