Does anyone have an opinion on replacing the payroll tax with a 1% national sales tax to fund SS and Medicare?
You mean add to, they will never drop one method for another only compound them.
A one percent sales tax wouldn't fund it. In 2012 we spend roughly $1.45 trillion on Social Security and Medicare. For a 1 percent sales tax to cover that you would have to have $143 trillion in taxable sales. That's considerably higher than our total GDP by a factor of 8 or 9.