Towards the end of his campaign rally in Phoenix this week, Donald Trump was determined to highlight some of his perceived accomplishments, as part of an absurd assertion that no American president in history has “accomplished as much as this president in the first six or seven months.” To that end, Trump turned his attention to energy policy:

“We’ve ended the war on beautiful, clean coal, and it’s just been announced that a second, brand-new coal mine, where they’re going to take out clean coal – meaning, they’re taking out coal, they’re going to clean it – is opening in the state of Pennsylvania.”

Let’s pause for a moment to note some of the relevant details. The idea behind “clean coal” – a phrase touted by the coal industry since the Bush/Cheney era – is a specific technique in which coal-powered plants try to capture emissions and bury the pollution underground via pipelines. The process is often referred to as “carbon capture,” but at no point does anyone “take out coal” and “clean it.”

A New York Times report noted yesterday that Trump administration officials sometimes like to stretch the definition of “clean coal” to refer to plans that “emit somewhat less carbon dioxide into the atmosphere than older coal plants.” Using the label this way paints a misleading picture, but even if we’re generous and accept this competing definition, what Trump told his followers in Phoenix still doesn’t make a lot of sense.

But the point here isn’t to just mock the amateur president who likes to talk about policies he doesn’t understand.

Those who’ve watched Trump closely since he entered electoral politics know he’s been talking about “clean coal” for quite a while. The president talked up the idea at a White House event in March, and even before the election, Trump embraced this as part of his campaign energy platform.

Even during one of the presidential debates last fall, the Republican touted his support for “clean coal.”

And yet, as of this week, it appears Trump has been advocating, with considerable enthusiasm, an idea he knows nothing about – which is inherently ridiculous. I don’t honestly expect any president to have vast subject-matter expertise on every issue, but it’s not unreasonable to expect a president to have some basic familiarity with his own ideas.

I have to wonder if Trump heard about “clean coal” at some point, and thought to himself, “Well, I like coal, and ‘clean’ sounds good, so I guess I’m for ‘clean coal.’” Spending a few minutes to get up to speed on the basics probably never occurred to him.