It's a semantics issue - by definition, any flat tax is a regressive tax.
So what ? Make more money or spend less. Those who defend progressive taxes are simply jealous and promote class envy.
Look at it a different way. If a person making $200,000 buys a $20000 car and a person making $100,000 buys a $10,000 car, doesn't the lower income person pay the same tax under the flat tax proposal ?
Message being, if the less wealthy folks stop trying to keep up with the wealthier Joneses and instead live within their means, their taxes won't be recessive.
No, a flat tax is NOT a regressive tax.