Scratch the surface of the year's biggest stories — the Iran war and AI — and both are bound up in the costs of energy.

Why it matters: Prices for gasoline, diesel and power are playing a prominent role in some of the tightest races for control of Congress.

• The war has kept gasoline prices way above $4 per gallon for months, and helped push diesel to record highs.
• Fairly or unfairly, data centers are getting blamed for rising electricity prices.
• It's all unfolding as affordability more broadly tops the agenda in races nationwide.

Here's a look at how energy politics are playing out in five critical contests...

Senate

Michigan. Power prices climbed faster than the national average over the past year in the Wolverine state, and data centers surfaced early in the Democratic primary and stayed prominent in the tight general election race.

• Former GOP Rep. Mike Rogers' campaign shows how Republican hopefuls are willing to split with President Trump on energy and AI — or at least get ahead of him.
• Rogers called for a one-year moratorium on data centers in August. And he called for a temporary ban on diesel exports in September, an idea Trump then flirted with but backed off.
• On the Democratic side, if Abdul El-Sayed's January "terms of engagement" for data centers looks familiar, it's because it reflects an increasingly common Democratic view around community buy-in and clean energy.

Ohio. AI's voracious appetite for electricity is fueling the clash between Republican Sen. Jon Husted and Democrat Sherrod Brown.

• Husted has made the case that data centers — not households — should pay for the new power plants and grid infrastructure needed to serve them. A bill he sponsored aimed at doing that fell short in the Senate after passing the House overwhelmingly.
• Brown is attacking Husted for previously championing data centers and tax incentives to attract them to Ohio.
• The fight encapsulates a broader question surrounding the AI boom: Who should pay for the massive buildout needed to power it?

Alaska. The Iran war is turning energy prices into a potent issue in the race between Republican Sen. Dan Sullivan and Democrat Mary Peltola.

• In rural communities, fuel already costs far more than in the Lower 48, with gasoline reaching $10 a gallon in some places. Peltola is tying rising fuel costs directly to Sullivan's support for the war, arguing higher diesel prices are hammering fishermen and families.
• Sullivan has called for temporarily halting U.S. diesel exports and argues Alaska should produce more of its own energy.
• Looming over it all is Trump's push for a massive Alaska project to export liquefied natural gas.

Keep reading for a look at two key House contests

Colorado 8th. This is a contest where energy could be the tipping point. Both general elections in the district's young history have been decided by less than 1%, and energy is prominent this time around.

• One thing to watch is how much political cover a recent data center vote gives incumbent Republican Gabe Evans.
• Evans' bipartisan Ratepayer Protection Act passed the House 417-3 last month. It urges states — but doesn't force them — to set rules ensuring data center developers cover generation and grid upgrade costs
• Don't sleep on gasoline either. New Democratic ads supporting challenger Manny Rutinel tie Evans to Trump's war with Iran and higher gasoline prices.

Pennsylvania 8th. Data centers have become a central issue in the House race between Republican Rep. Rob Bresnahan and Democratic Scranton Mayor Paige Cognetti.

• Northeastern Pennsylvania is fielding proposals for the energy-hungry facilities. Cognetti is campaigning explicitly against projects that raise electric bills, threaten water supplies or receive tax breaks.
• Bresnahan, who has previously supported data center development, has introduced legislation aimed at protecting local governments that reject projects from corporate lawsuits.
• The fight captures the emerging politics around AI infrastructure: Communities may want the investment and jobs, but they also want control over the costs.

Sometimes the outcome of a Supreme Court case becomes pretty clear during oral argument. Yesterday was ... not one of those times.

Why it matters: The argument creates a cliffhanger over the fate of dozens of state-court lawsuits nationwide seeking climate damages from oil giants.

The big picture: Justices are weighing whether federal law blocks Boulder, Colorado's claims under state law.

• They're also mulling whether the Colorado Supreme Court decision to let Boulder proceed was a "self-contained" action that gives SCOTUS jurisdiction.

👟 Catch up quick: Samuel Alito's recusal means if all the liberal justices side with Boulder, one defection among the conservative majority creates deadlock.

• That would allow Boulder to proceed, but prevent a wider precedent on these kinds of cases under state law.

🏀 State of play: Good argument recap pieces are already out there, so let's jump to how legal analysts (and yours truly) are thinking about what went down.

• Justice Brett Kavanaugh seemed to clearly side with the oil companies that federal law preempts the state claims, citing a "wall of precedent."
• Justices Ketanji Brown Jackson and Sonia Sotomayor seemed likely to side with Boulder, while Elena Kagan was somewhat hard to read, multiple analysts noted.

📣 What they're saying: UCLA law professor Alejandro E. Camacho's insta-analysis breaks down like this:

• Justices Jackson and Sotomayor "firmly" with Boulder. Justice Amy Coney Barrett "leaning" toward the oil companies, but not on broad constitutional grounds they raised.
• Justices John Roberts, Neil Gorsuch, and Clarence Thomas' views are uncertain, though Thomas may be leaning toward the companies and Roberts was "harder on Boulder."

🔭 Zoom out: Camacho thinks the most likely outcome is the companies winning on narrow grounds.

• Of note: Camacho's on the board of the Center for Progressive Reform, an NGO that supports Boulder's position.

My thought bubble: A bright spot for the oil companies is that multiple justices seemed wary of a practical mess in the absence of federal preemption.

• "Presumably, if you prevail, the next day, a municipality in every single state will file a lawsuit," Roberts told Boulder's attorney.

🔍 What we're watching: There's potential for a mixed outcome that blocks these state claims about emissions but preserves the power to bring deceptive practices claims.

• "A narrow preemption ruling would do little to shield fossil fuel producers from state and local liability," write Shuting Pomerleau and Misha Mazalevskyi of the American Action Forum, a center-right think tank.

The bottom line: "I think all of the conservatives other than Kavanaugh are in play. Kagan may be as well," William & Mary environmental law scholar Jonathan Adler said via email.

President Trump issued an order last night designed to effectively allow truckers to use diesel meant for farms and other off-road equipment.

Why it matters: This diesel is typically exempt from federal taxes of over 24 cents per gallon applied to its on-road counterpart.

• The White House said the move would save truckers around $60 on a 250 gallon refill, and over $100 where states match the effort.

Catch up quick: It tells the Treasury Department to defer the taxes through the remainder of 2026, and orders Treasury to "explore pathways," including legislation, to never collect them.

• It also urges more states to provide tax relief.

Reality check: "[C]omplications, including that framework and patchy enforcement, prevent the entire national fleet of diesel consumers from benefiting," writes GasBuddy analyst Patrick De Haan.

• Uncertainties about deferment and the interplay with state policies lead De Haan to conclude that many major truckers won't take the risk.

The bottom line: Trump lacks tools to deliver a sharp and sustained cut in diesel and gasoline prices as long as the Iran conflict and attacks on Russian refineries drag on.

• But he's pulling multiple levers that can bring limited relief, such as Jones Act waivers, pushing Europe to release diesel reserves, and now the new order.

Google this morning announced a power purchase deal with Constellation Energy that will finance a combined 890 megawatts of higher output at nuclear plants in Illinois, Pennsylvania and New Jersey.

Why it matters: That's enough to power hundreds of thousands of homes, and represents the latest move by tech giants to bring more electricity online as data centers boost demand. Bloomberg has more.