Sen. Ruben Gallego (D-Ariz.) is pressing the Energy Department for details on plans to provide oil from the Strategic Petroleum Reserve as pump prices rise. Why it matters: Gallego's new letter to Energy Secretary Chris Wright, viewed first by Axios, shows how the energy effects of the Iran war are spilling into Capitol Hill — and politics more broadly.Gallego is a potential 2028 Democratic presidential hopeful.Driving the news: The letter asks how the SPR move will affect gasoline prices and supply in Arizona, as well as questions about the planning process.The big picture: The Energy Department plans a phased distribution of 172 million barrels of crude from the nation's strategic oil reserves.It's part of a wider planned release of 400 million barrels from various member governments of the International Energy Agency.Catch up quick: DOE confirmed Friday that the U.S. action will be an "exchange," under which companies will return borrowed oil with additional barrels as a "premium."This will strengthen the SPR "while stabilizing markets at no cost to American taxpayers," the department said.It issued a request for proposals for the first 86 million barrels. Friction point: The letter from Gallego, who has recently boosted his energy profile, also seeks information "on how your Department plans to relieve Arizona's exceptionally high gas prices through releases from the Strategic Petroleum Reserve."The other side: Trump administration officials are seeking to tamp down public concern about gas prices, which per AAA data have risen over 70 cents per gallon on average since the strikes on Iran began.President Trump told reporters Friday that U.S. gasoline prices "are going to come tumbling down" when the conflict is ended.And top officials have been saying they expect the war to end within several weeks.What we're watching: Look for the war to keep surfacing in midterm election races and early jostling in the 2028 White House race.