The day you "abolish the IRS" is the day you eliminate taxation altogether—which of course will never happen. As long as there are taxes, there will be an IRS to collect them in some form.
My $.02 on this idea....'
(1) Others also seem oblivious to the fact that there are other nefarious functions within the IRS to torment, control, or leverage the populus or tip the scales of balance politically? Did everyone forget how one particular president used the IRS to give certain entities exemption status or not. Executive and Legislative Branches are not going to cede that power.
(2) Tax will be seen as highly regressive in nature. In this system every shares in the tax burden uniformly. That will never get by the obstructive left, will never get the legislative support, and even if it did, would be subjected to so much court review..... It'd die in the next administration, or party change.
(3) Early on, the added up front sales tax... 15%, 20%? would have adverse purchase impacts of perceived initial higher cost. I know that sounds ludicrous, but when you have most of the population living pay check to paycheck, and no savings...... Fiscal IQ of the average American is poor.
(4) New system will be as rife with fraud and circumvention as the old. New levels of black market systems on large ticket items will be rampant. Barter will expand exponentially. People will buy foreign, outside the watchfall eyes of sales tax collectors. Tax inlays will come up woefully short of expectations.
Don't get me wrong. I would absolutely love a natiional sales tax, becasue I am a miser, obsessive investor, spendthrift, and would come out a huge winner in this kind of change. But the one thing that puts a dagger in this idea at square 1, is that removing complicated enforcement driven taxation is a tool and a weapon that our government will not relinquish.