Certainly NOT the sort of "from each according to his ability to each according to his need" sort of "fairness" that Marx and Engles proclaimed in their Manifesto, which btw is the genesis of the modern progressive income tax. That is what liberals love. The ability of the government to use the tax system as a social engineering tool to reward the behaviors they like and punish the ones they don't.
The sort of "fairness" fairtaxers speak of is a level playing field where EVERYONE gets a bite at the apple without regard to what uncle sugar likes or doesn't like this week!
How so? FairTaxer FAQ indicates the fairtax has about the same level of progrestivity as the current system, and besides the fairtax does absolutely nothing as far as what goodies Uncle Sam doles out. You guys just love to claim benefits where there are none.