It won't be easy, but I don't think it's impossible. Many countries have a VAT (value added tax) or GST (Goods & Service Tax) that could go some way to achieving this goal. The problem is that poorer people spend a higher percentage of their income on goods, so you'd need to make things like milk, bread, fresh fruit & veggies, baby products, etc exempt. I don't work in tax but I think it is possible.

I don't think the dual taxation issue is about ability. It's about will. An Australian citizen working in the US only has to pay tax in the US, but an American citizen working in Australia has to pay tax in Australia and the US. Australia's tax system isn't more advanced than the US... but the Australian political parties know if they tried to implement dual taxation they'd be ousted in the next election.

It's really bad that in the US corporations have so much clout, but I think a huge move to remedy that is to repeal the Citizens United decision. Closing the gaps so that corporations cannot donate to politicians would help resolve this a lot.