If the goal is jobs, we need to look at what will encourage an employer to add more people. First, let's give a tax cut to wealthy people. What will they likely do with it? They probably have pretty much all the stuff they need so will probably save or invest it. That means more money available to be lent out. If you are a business, will you hire more people becasue there is more money available to borrow? Unless you already want or need to borrow, that will not enter your calculation to decide to hire or not hire more people.
What is more important? Demand for what you are producing. If you are having no problems making as many goods as you can currently sell, you won't be adding more workers. Unless you think you can sell more goods than you currently do. More money going into saving and investments is not going to change the demand for your goods and services (unless you are selling financial services).
Now lets give the same dollar worth of tax cuts to lower income people. They have more pent up demand and are more likely to go out and spend most of that money instead of saving it. This DOES increase the demand for goods and services. As companies see demand for what they produce rising, they will eventually hire more people (after first trying to get more out of current workers). This is creating more jobs.
Thus, if the goal is using tax cuts to increase jobs, give the money to those at lower incomes will be more effective than giving the same dollar value of tax cuts to the wealthy. In the case of the Bush tax cuts, most of the benefits went to those at higher income levels so it was not very effective as an economic stimulus and ended up adding to the budget deficit (since they were not offset by comparable reductions in spending which instead was increased to fight two wars).