What's driving up the price of gas?

Damned if I know, but it's for sure you'll never find out if you listen to the networks. Reading the recent batch of their stories (and watching their broadcasts) you can almost hear their collective shoulders shrug:

Headlines simulated

ABC News: Gosh, prices are really high. So high, even NASCAR fans are affected.

CBS News: Gas prices went up, fast. Why? How should we know?

NBC News: Oil prices surge. It could be the weak dollar, or Turkey, or Nigeria. Iran maybe? Hell, your guess is as good as ours.

I'll give NBC News credit – they at least have a story debunking the gas tax holiday and their story provides some speculation (albeit without any context or supporting facts – "X happened, but how much of the market does X affect? Has X affected the market in a similar fashion in the past?")

Here's Nieman Watchdog on the same topic – they may not have all the answers, but at least they are asking the right questions:

10 tough questions on oil and gas prices

Twenty or thirty years ago, a rising oil price could be counted on to eventually bring more oil into the market. Not so today. The question is why,

[snip]

Gas prices are most politically relevant because they are a sharp pain that voters will be feeling this summer and fall, before they vote. All three candidates (and even President Bush) seem to "get" this. But the summer holiday for the 18.4-cent federal excise tax on gasoline proposed by Clinton and McCain will not, in the view of the experts and the media, do much more than slightly numb the voters before their wallets are amputated.

[snip]

While crude prices are a factor, most experts would agree that tightly limited U.S. refinery capacity is also a big factor in pushing domestic gasoline prices higher.
Less easy to answer: why is refinery capacity limited and what can be done about it?

Some numbers: In 1981, there were 324 refineries with a total capacity of 18.6 million barrels per day, according to the EIA. As of 2007, there were 149, with a capacity of 17.4 bpd.

It is no secret that the industry deliberately shut refineries (PDF) to improve profits in recent decades. Industry says it is now building new capacity at existing plants – but despite rising prices and growing demand, refineries are again cutting back their capacity-building plans.

Okay, it's a little too easy to say "gosh, those multinational oil corporations are driving up prices" but how's about some news coverage that at least explores the question of why we have less than half the refineries we had a quarter century ago? – or why market collusion (like we saw in the California energy crisis) can be eliminated as a suspect? – or at the very least could someone identify the barriers to finding out this information?