High diesel and gas prices are hammering American families and have pushed Trump's standing on inflation to the worst level ever recorded for a president — bad news for him and for anyone buying groceries.

• The war with Iran has squeezed oil supply, and diesel has climbed past $8 a gallon in California and near $7 in Georgia.
• Everything that moves by truck — food, household goods — gets more expensive when diesel does.
• Washington answered with a 90-day emergency rule letting fuel truck drivers work longer hours, which does nothing about the actual shortage of oil.
• Trump brushed it off at a North Carolina rally, calling the cost a cheap price to pay, while a Fox News poll shows most Americans call gas and grocery prices a major problem.
• His net approval on inflation now sits 61 points underwater, and Republicans in Congress are starting to break with him publicly.

Outlook: Unless the Iran conflict winds down and fuel prices ease, the political damage will keep spreading through his own party.