I second Bob Budding. It's not about political bias. It is a fact that Republicans tend to ignore the existence of this stiff tax when it is a major fact of life for a worker who gets $8 or $10 an hour. And if you read "The Coming Generational Storm" which I coauthored with economist Larry Kotlikoff you'll see that it doesn't matter what you call a tax. What matters is what goes out and what eventually comes back. Net the two and you have the lifetime taxrate that a worker may pay.
Take that approach, which is called generational accounting, and you'll find that the effective tax rate most young workers will pay on their lifetime income is far higher than the lifetime tax rate older workers and retirees have or are paying. Politicians of both our wretched parties like to give taxes different names and take them out of different pockets just to keep us all at each others throats. The reality is the BOTH parties have made promises that can't be fulfilled.
Beyond the book, I've written lots on this subject and every column has links to supporting sources.
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Scott
Scott