[Chuckster]

"4. tax-and-spend politicians in Congress would never allow it because it might ultimately reduce the amount of revenue they get to spend. There's no initiative/referendum process for citizens to change the IRS system, so the only way would be to elect supporters of abolishment of income tax. (and that's hard)"

Your #4 (above) says it all. Government is just too big and will not get any smaller unless drastic action is taken which is highly unlikely. But we can still dream, can't we?

[heleny]

Government is just too big and will not get any smaller unless drastic action is taken

Move election day to April 16th, when heavy tax burdens are still fresh in many minds?
Perhaps bond measures (which rely on taxes to be repaid) might get defeated more easily.