Congress will never vote to remove the majority of its power. Want an national sales tax? Sure, you'd likely get it. Income tax would disappear, IRS would get a name change, you'd pay more when you bought things. Few years down the road (under best of circumstances), something would happen and another tax would be added. Then another. Then another. Then you'd likely get some form of income tax. Likely it would be hidden, but it'd still occur.
I am pretty pumped about the idea of deleting all federal taxes, excise, sin, social security, income, gasoline, etc. for the consumption tax and think now is the best opportunity we have to get tax reform. One element that is intriguing is the fact that it would set a precedent for smaller govt. Many bureaucracies exist only because of taxation or enforcement. Wouldn't it be nice if some of the alphabet agencies went away?