And the only way large numbers of consumers can buy more goods and services is if they have more money to spend. This can be done by raising wages for the poor and working classes, or by cutting their taxes (and yes, they do pay taxes regardless of what the GOP would have you believe). When the poor and working classes (and many in the middle class) get more money, they have to spend it because they are barely getting by -- and when they spend that money, demand is created. And when demand is created for more goods and services, the rich will invest in new jobs to meet that new demand (so they can make more profit).
That is the way our economy works. It would be stupid for a business to create new jobs that are not needed (because demand has not increased). That would just lower profits -- and companies are in business to make a profit, not create needless jobs. It is only when more profit can be made (because demand has increased) that it makes sense to create new jobs.
Anyone who tells you that jobs can be created by cutting taxes on the rich is LYING to you -- and it is a lie that makes no business or economic sense.