Except that a plan for raising the rates on about half the people in the country is going to give the Democrats the 'class warfare' flag to use against the GOP. And don't think they won't be waving it for all they're worth.
The biggest problem I forsee is the temptation of congress to slowly reintroduce deductions for various things.
The biggest problem I see is getting the majority of people to vote for a man who has said they will raise their taxes.
The argument that needs to be emphasized is that prices will go down more than enough to cover any "tax increase." I'm not sure how much of the current price of food is taxes (I'm pretty sure some fair taxer can find this) but I know it's pretty substantial.
Lowering the business tax rate from 35% to 9% will cause the price of food to drop more than enough to cover the additional federal sales tax. At the end of the day, the consumer will walk out of the store having paid less (including sales taxes) than they do today.
The other things that need to be emphasized are:
I admit it's a complicated argument, and we live in a sound bite society.