Should be 100%. Federal Income Tax is unconstitutional.
That being said, the 45% non-participation rate shows we are in the "bread & circuses" phase of our decline.
This kind of comment just makes conservatives look stupid. The income tax may be immoral, it may be unwise, it may be economically stupid, it may be against the desires of the Founders - but it is not unconstitutional. Why? Because it was added to the Constitution via the method provided by the Founders, the constitutional amendment. We might disagree with it, we might want to repeal it, but please stop saying it is unconstitutional. It is not any more unconstitutional than freedom of religion, freedom of speech, etc. - which were also added to the Constitution via the amendment process.