You can not cut income taxes on 95% of Americans because almost 50% don't pay ANY income taxes now. Tax issues are very complex because people talk about them in different ways depending on their viewpoint. It is important to do a little research about income vs payroll taxes. I would suggest you look into the Fair Tax which is a plan to replace both with a consumption tax. If you read about this, you can not help but learn about the other types of taxes as well. The Fair Tax book is easy and quick reading.
Americans For Fair Taxation: Americans for Fair Taxation