The only viable option for real tax reform is to trash the income tax(both individual and corporate) altogether and drastically reduce the IRS and it's powers to screw over US citizens.
The reduction, or even the elimination of the IRS and replacing it with some other agency with only the power to collect sales taxes, would save millions of dollars a year. Not to mention eliminating one of the weapons that the feds use to intimidate each other and to use as a weapon against anyone who disagrees with them.
This article is about CALIFORNIA, not the nation as a whole. It is much easier to cross state lines to shop than it is national borders. This makes it critical not to rely on a single very high sales tax for revenue — people avoid a high-rate tax in situations where they would not bother if the rate was lower.
You said “add 5% to the sales tax”, and did not say you would include all goods and services. The current sales tax is roughly 9% including the state and county/city rates, but it applies to only 30% of purchases. This revenue would be effectively replaced by a 2.7% tax rate if it applied to all purchases. Instead, you want a 14% sales tax rate on all purchases ?? You want a 500% tax increase ? That is overkill. A sales tax rate that applied to all purchases would only need to be 7% to replace both sales tax and income taxes in CA, plus the extra 1% county/city sales tax. That means a total 8% sales tax to replace both sales and income taxes. Not your 14% rate. Even at 8%, you will get a lot of flack from retirees who are spending savings they already paid income taxes on and now will be taxed again when spending it. By lowering the sales tax to 5% on EVERYTHING, their overall situation is not much different than the 9% they are currently paying on “non-necessities”.
By retaining the income tax at 3%, you still collect money from people earning in CA even if they save their money and later run off and spend their money elsewhere. Two low rate taxes, neither of which is worth much effort to evade, are superior to a single high rate tax which can only encourage evasion.