Diesel fuel prices hit an all-time high on Wednesday, while gas prices jumped another 7 cents in a single day and the stock market headed for another selloff because crude oil prices rose above $100 per barrel again.
The timing couldn’t be worse for Republicans, who are gathering in Dallas to fine-tune their message ahead of midterm elections that focus on the cost of living.
The Republican National Committee said it will contrast the Democrats’ “radical policies” with their efforts to lower costs and establish energy dominance. But their message is undercut by a midweek surge in costs tied to President Trump’s war against Iran.
Brent crude futures traded above $100 per barrel for the first time since July because of an increase in strikes between the U.S. and Iranian militaries and Tehran-backed Houthi attacks on oil facilities in Saudi Arabia.
Stocks fell on the second day of the holiday-shortened trading week as investors sized up the war and related oil prices.
Crude oil is the main ingredient in gasoline, so American drivers are paying more.
The average price of gas was $4.22 per gallon on Wednesday, up 7 cents from the prior day and 42% since the war began, according to the AAA motor club.
Diesel set an all-time high of $5.94 per gallon on Wednesday, an increase that could raise prices of other goods as shippers pass along higher fuel costs.
Mr. Trump says the U.S. is winning the war against Iran, which he launched on Feb. 28 to prevent Tehran from gaining a nuclear weapon.
The president has tacitly acknowledged the economic pain, though mainly to say it will be short-lived.
“Oil prices will drop precipitously, like everything else is dropping (but more!), when we WIN the war with Iran,” he said in a recent post on Truth Social. “Three Dollars a gallon, but ultimately, below Two Dollars a gallon. It will all happen quickly, and Iran will never have a Nuclear Weapon.”
Both nights of the first-of-its-kind GOP midterm convention will focus, in part, on “affordability,” the main buzzword of this election cycle.
Public polling shows voters stress the economy and the cost of living over other issues.
Mr. Trump is keenly aware of the concern but says Democrats are to blame for high inflation that peaked during the Biden administration.
The president points to signs that inflation rates stabilized in recent months and recounts how he got egg prices under control in the first weeks of his term.
Yet Republicans are battling sagging poll numbers and fretting over competitive races in once-solid districts.
The party controls both the House and the Senate, but could lose both chambers in November if Republican candidates fail to win close, swing-district races and statewide races.
Key races in typical Republican strongholds, including the Senate races in Texas and Iowa, are suddenly competitive as Democrats hammer Republicans over the high cost of living that is vexing voters.
The Democratic National Committee on Wednesday mocked Mr. Trump over high gas prices as the GOP convenes in Dallas.
“As Donald Trump and his Republicans kick off their dog-and-pony show, everyday Americans are grappling with gas prices that just keep getting more expensive,” DNC spokeswoman Kendall Witmer said. “Instead of providing any relief to working families, or fixing the mess they created, Republicans are focused on inflating Trump’s ego. Voters will remember who is fighting to lower costs come November.”
The Trump administration is pointing to workarounds to get oil flowing out of the Middle East and return flows through the Strait of Hormuz back to prewar levels.
Iran clamped down on shipping in the strait, disrupting global supply and rattling markets, but Mr. Trump imposed a naval blockade to direct ships through the channel.
“President Trump remains committed to unleashing American energy dominance, cutting costs, and putting more money back in the pockets of hardworking American families,” White House spokeswoman Taylor Rogers said Wednesday. “Last week the president met with nearly a dozen refiners to discuss ways to expand our refining capacity, which will lower prices at the pump. As the U.S. continues to maintain full control of the Strait of Hormuz, oil and gas prices will fall back to pre-conflict levels.”
• Susan Ferrechio contributed to this story.

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