All Bush did was take out a big loan on people's behalf. Pure socialism, the government decides to take out a loan and lend people the money hoping the tax receipts will cover the interest if they make profits with it. What happen to the individual doing this for himself and the government staying out of it?

The graph take into account what the private sector does with the money, it's a very old concept called a multiplier. If a part of the economy gets more money from a source then when they spend it they generate more business for others. The important point is that if it doesn't generate enough to pay for the stimulus then even though it might be quite successful in many ways it adds on debt.

It's like a business that grows but always loses money. No matter how big it gets it has to turn a profit one day. Supply side economics stimulates the economy to some degree but it doesn't show a profit. So eventually you have to stop doing it and raise taxes because the debt becomes too large.