As Memorial Day weekend approaches, national Democrats are testing out a new line of attack against Donald Trump. Nope, it’s not about the new evidence accumulating every day that the president bases major policy decisions on how they affect his personal wealth. The Democrats’ strategy is all about pinning a moderate rise in gas prices on Trump.

Earlier this month, Senate Majority Leader Chuck Schumer and the Democratic National Committee put out a “sprinkling of statements” blaming Trump for higher gas prices, the Daily Beast reports, the opening salvos in a sustained, coordinated messaging campaign by the party.

Across the country, gas prices are rising.
It’s clear who to blame: @realdonaldtrump pic.twitter.com/eKxq4yDjD0

— Senate Democrats (@SenateDems) May 21, 2018

Gas price populism is nothing new. Despite the absence of any firm connection between White House policy and the price of fuel, blaming the sitting president for more expensive gas is a timeworn political tactic. Though only Republicans routinely work themselves into full-on drill-baby-drill mania, we’re now seeing that Democrats are fully capable of turning an uptick in gas prices into electioneering fodder.

It’s a maneuver that sits uncomfortably next to Democrats’ position as the major political party that views global warming as serious threat.

Few things are more damaging to the climate than cheap gas, which incentivizes more driving, the purchase of less fuel efficient cars, and sprawling development patterns. As economist Joe Cortright has written, Americans get “locked in” to larger cars with worse fuel economy for the lifecycle of the vehicle — which can be more than a decade.

Even with the increase in fuel prices in the past year, gas remains relatively cheap by recent standards:

And by the standards of international peer nations, America does not pay much at the pump:

The longer America’s addiction to low fuel prices continues, the harder it will be to make a transition to carbon-efficient transportation and development patterns. Democrats are going to tie themselves in knots if they try to be the party fighting for cheap gas and against global warming at the same time.