Politicians like to spend, and they don't like to tax. When they can get away with running a deficit (see: Federal government), they do so. When they cannot (see: state and local governments), they resort to a variety of tricks, including the ultimate in robbing Peter to pay Paul, begging for Federal money. At the end of the year, the budget balances because it has to.
The problem is that they're too busy spending on new programs during boom times to think about how this is all going to work out during a downturn. When property values are on the rise, increasing property tax revenue, and businesses are moving in, increasing both business and personal income tax revenue, everyone is happy. Tax rates can stay the same, spending can increase, and it's good times all around. But when revenue starts to fall - when property values fall and unemployment increases - something has to give.
In a household, when income goes down, people cut back. They go out to dinner less often, or eat cheaper cuts of meat. They don't go to Europe for vacation, they head to the local beach. They hold on to that old car a little longer. In government, the idea that they can no longer afford the extravagances of the good times is a foreign concept. They'll play games: "We saved some millions of dollars by not staffing vacant positions!" They'll shift costs to other taxpayers: "We saved $300 million by stiffing the state university system, which induced the university to institute a tuition increase to make up the $300 million." (Both examples are from the great state of Maryland, by the way.) At the same time, they'll propose new spending, on new programs. Just because they can't help themselves. Arlington, Virginia has a budget problem and plenty of privately-run places for art, but they managed to budget millions more for a publicly-run art gallery.
The one thing they can't do is cut programs and cut spending. I blame part of the problem on the fact that an increasing fraction of the electorate pays no income taxes. (Close to half no longer pay federal income taxes.) Heck, if I'm not going to pay for the new park, or for printing ballots in an obscure dialect of Mandarin, what do I care? Bring it on! But the politicians also seem incapable of saying no, especially if it's "for the children," "for the poor," "for diversity." This is how we end up with schools that cost more than $10,000 per student per year, yet produce students who are generally inadequately prepared for college; how we end up with multiple, often overlapping, programs for the poor that cost a fortune but don't actually reduce poverty; and how we create a society so concerned about racial, gender, or ethnic sensitivities that we can't talk about those topics.
Amusingly, because most people don't like taxes imposed on them (on other people - on the "rich" - sure, go right ahead, tax away; just don't tax me, buddy), but there aren't enough rich people to pay for the projects that politicians insist upon, we've seen a huge increase in taxes and fees other than the personal income tax. These range from taxes on businesses - somehow you can fool people into thinking that higher costs for businesses don't translate into higher prices for products - to taxes on "sin goods" (cigarettes and liquor), to user fees - highway tolls, higher fees at the DMV - to higher gasoline taxes, to an increased reliance on gambling revenue - state-run lotteries, casinos, sports betting, and the like. What all of these things have in common is that they are all regressive taxes; that is, the tax burden tends to be higher the lower one's income. The poor smoke at a much higher rate than the rich, so a cigarette tax hits the poor harder. The poor spend a disproportionate fraction of their income on fuel, so a gasoline tax hits the poor harder. And so on. These politicians, many of whom profess to be "progressive" (an Orwellian term itself), choose to fund their pet projects, their art galleries, their skateboard parks, and so on, on the backs of the people they profess to want to help. It would be funny if it weren't so sad.