Taxes have been unconstitutional ever since the Citizens United ruling.
Once it is determined that money is speech, and so long as the Constitution prohibits Congress from making any law abridging freedom of speech. then Congress can make no law telling you how to spend your money. Making laws that require you to pay some of your money to the government is then clearly unconstitutional.
I’m really surprised that no one has yet brought a suit testing this. It provides an interesting dichotomy: Either Citizens United was wrongly decided or else Congress has no power to tax (at least not to require money in payment of taxes) for all that Congress’s power to tax is written into the Constitution.