The cost of refuelling pickup trucks, SUVs and other all-American forms of transport threatens to become the latest election talking point after petrol prices hit a record high in California, home of the nation's busiest freeway system.
A gallon of regular fuel cost an average of $4.61 (equivalent to 76p a litre) across the state yesterday, surpassing a record set in 2008. Analysts say it could hit the symbolic $5 barrier in the coming days, and there are reports that panic buying has caused some service stations to run dry.
The price surge comes amid speculation by oil traders responding to hiccups in the local supply chain. A power cut at a major oil refinery in Orange County last week added to the burden of ongoing fallout from an August fire at a second important refinery in Northern California.
"This is so depressing!" one motorist was quoted as saying on the front page of the Los Angeles Times. Another declared: "I don't know why this is happening!" An analyst told the Associated Press that the steep rise in prices reflected a "perfect storm" of circumstances.
California's spiralling prices are not mirrored across the US: national average pump prices ticked down at the weekend to $3.76. But California's surge has been widely (and apocalyptically) covered by cable news outlets, partly because it speaks to one of Mitt Romney's campaign talking points.
The Republican candidate has frequently observed that US petrol prices have "doubled" under President Barack Obama, taking money from the pockets of middle-income families. He repeated the claim during last Wednesday's presidential debate, which he was widely considered to have won.
Fact-checkers describe Mr Romney's contention as true but misleading. In 2008, the year before Mr Obama took office, oil prices were highly volatile, oscillating between roughly $30 and $140 a barrel. As a result, the price of petrol also fluctuated wildly. For much of the year the national average was above $4 a gallon, hitting a then-record $4.11 in July. But the financial crisis caused it to fall dramatically, and by the end of the year it had touched $1.61.
After Mr Obama was sworn in, national pump prices returned to their historic parameters, which remain below the highs of 2008 but are also double the year end's lowest figure, allowing Mr Romney to make his claim.
But context matters little in an election campaign, and according to Mr Romney's narrative, Mr Obama has burdened motorists by introducing unnecessary environmental regulations and failing to approve important oil exploration and infrastructure projects.
It is a theme that speaks powerfully to middle-income Americans. Although the US has cheaper petrol, and lower fuel taxes, than almost every Western nation (motorists pay on average just 30 cents of duty per gallon) it also has some of the world's longest commuting distances and least efficient fleets of vehicles.
The continuing coverage of California's petrol "crisis" will help Mr Romney maintain his agenda in advance of Wednesday's vice-presidential debate between Paul Ryan and Joe Biden. It may also protect his recent bounce in the polls which averages 2 to 3 percentage points but still leaves him slightly behind Mr Obama.