A mindset won't change becuase you legislate it (as proven so poignantly by the civil rights movement).
Like hell it is. Taxes exist because a government cannot function without monetary input from the people it governs, and we chose at the onset of this country to have a government to govern the people. Funding government processes is the only function of taxes. Forcibly taking from others what they won't willingly give in order to give it to somebody else is neither a function of taxes nor a function government.That's why taxes exist; because we can't simply depend on people to do the right thing.
You have neither a legal or moral argument to support this. It's my right to choose not to help someone just as it's my right to choose to help someone, and unless I am in a position held legally accountable for providing aid (sworn state workers, for instance) then there is no legal or moral argument to support forcing me to help.So yes, the rich need to pay more to help spread the wealth because they're not going to do it just because we ask really nicely.