Re: $514 Bil Deficit is too Pessimistic.
Why is it Ok for government to run up deficits, but it's not ok for common folk like you and I? If I borrow money, I MUST pay it back. Why do we hold government to such a lower standard?
As noted, governments exist into perpetuity. Citizens do not.
Plus, the government does pay off its debts. When the government borrows, what it does is issue bonds or Treasury bills, which pay out at specific interest rates over a defined period of time. So if you buy a 52-week T-Bill today, the government will pay you the amount plus a 0.11% interest 52 weeks from now. (Note that if you let it roll over, then you've delayed the date and increased the amount the government has agreed to pay you.)
If the government did not pay out 100% of what it owed, then the government would default. So, when the Republicans refused to raise the debt ceiling, the US government almost had to default on its debts -- not because it ran out of money, but because Congress temporarily refused to authorize those payments.
Some say that deficits are an "economic stimulus." But why is it that government debt is an economic stimulus but private debt is not?
Both can qualify as a stimulus, or have a minimal impact. It really depends on how the money is used.
For example, let's say I take out an equity line of credit on my house. Technically speaking, I have generated $100,000 of credit, but the bank isn't actually loaning me any money until I draw on that line of credit. Technically it's debt, but practically speaking if I never use it then it has no economic effects.
Or, let's say I'm an idiot, and I draw on that line of credit to pay for a week vacation in Paris. None of those funds stimulate the US economy.
Or, let's say I'm still an idiot, but I draw on the line of credit to take a vacation somewhere inside the US. Those funds will stimulate the economy.
As for the government, some types of spending have bigger impacts than others. For example, military spending is generally regarded as having a "low multiplier," because some of that will go to people's salaries (much of which gets spent, and thus goes back into the economy) while some goes into products that basically dead-end. E.g. a tank may be useful from a military perspective, but does not really benefit the economy.
Similarly, pork-barrel projects will have a minimal impact. If a state builds a bridge that sees almost no use, that also winds up with a low multiplier.
In contrast, spending on a bridge that really is used and actually needs repair, or spending on food stamps, is usually regarded as having a higher multiplier. E.g. the government gives Joe "Minimum Wage" Walsh $100 to spend on food, and only food; Joe goes to the market, and buys $100 worth of food. That $100 goes to the supermarket and the food manufacturers, who in turn pay their vendors (more economic activity) and their staff, who in turn go out and buy more stuff.
From whence comes this notion that government is perfect, and every dime it spends is better than you or I spending that same dime?
No one thinks government spending is "perfect."
The advantage is that in a recession, no one wants to spend or loan any money, and they are shoving it under the mattresses. If the government borrows big bucks, and spends it on needed infrastructure and short-term benefits, then that money is getting "unlocked" and spent, with the government's guarantee that it will be paid back.
Furthermore, if deficits are so "stimulating", then what do we need taxes for?
At the risk of stating the obvious: Taxes are the revenues that we use to pay for services, and pay off those debts.
Without taxes, the government would be like an unemployed guy who keeps paying off credit cards with other credit cards. Even if the guy is making work for other people, eventually someone is going to recognize that he has no revenues and is unable to pay off his debts.
In addition, the federal government's revenues are still huge. E.g. in 2012, the US spent $3.5 trillion and took in $2.45 trillion. Without those revenues, the deficit would have been $5.95 trillion, instead of $1 trillion! That's clearly not sustainable.