However, a Ponzi has no real means of generating substantial income, earlier investors are paid money invested by those who join the scheme later. Banks, on the other hand, have a multitude of ways of generating substantial incomes through interest earned in business and housing mortgages and loans, fees etc. Their profit is based on the difference between the cost of borrowing money and the interest charged for loans. Depositors are happy because they don't have the headache of dealing with possible collection problems and their principle and interest is guaranteed by the bank. Dealing with these kinds of problems with the accompanying risks is the speciality of the banking industry.
Banks have to work to earn their profits.
I don't see how this is related to a ponzi scheme. The only work involved in a ponzi scheme is to promote the scheme. It goes to where it came from, nowhere. So, when a politician or anyone else tells you that they want to reduce the deficit or reduce the national debt, he's either lying to you or is too ignorant to know what he's talking about.