There absolutely can be a price shock that will make current prices look economical. Oil is priced on a global market, and if the price is high enough, that might mean many Americans are priced out of some of their own oil. The only way to decouple the domestic and international markets is export and price controls. One need only look to Canada's NEP of the 80's to understand how that's likely to turn out.

Also, the U.S. is currently prosecuting a trade war against Canada that has, thanks to Trump, become a question of sovereignty for Canadians. The U.S.'s largest source of foreign oil is, potentially, one outburst from Trump away from Canada placing export duties on oil. It has been discussed in Canada, and it's viewed as an extreme option, but an option nonetheless. Trump would have to say or do something truly outrageous for that to happen, but his ability to turn allies into enemies should not be underestimated.

Bottom line, fuel could become a lot more expensive, quickly. Even if there's still gasoline to be had, it still qualifies as a shortage if it becomes unaffordable. Fuel prices affect food production, delivery of goods to markets, and pretty much every aspect of the economy.

Oil tankers travel at about the speed of a bicyle. If a price shock does happen it will last for months. If the war with Iran is not resolved promptly, this is precisely what will happen.