Niskanen's argument is interesting. He says that you must cut pork, but the pressure to cut pork comes from voters feeling the pinch of taxes. Some modest tax burden encourages greater responsibility for the programs funded by those taxes. If the tax burden were zero, there would be zero incentive to cut any programs - ie, because you are spending some else's money.
Excellent comment. That's why I feel that a fair tax system should be one that causes equal agony to everyone.
There is an old saying; "The government that robs Peter to pay Paul can always count on the support of Paul." As long as the politicians arrange taxes so that there are more Pauls than Peters they keep getting re-elected. The unfairness to Peter is of no concern to them.