A month ago today, during one of only a few conversations with Democratic congressional leaders about the government shutdown, Donald Trump began the meeting with “a 15-minute profanity-laced rant about impeachment.”

No one could say with confidence what prompted the tirade – the threat of impeachment wasn’t the point of the meeting, and no one had brought up the subject before the president did – but Trump’s harangue was emblematic of his preoccupation with the subject.

The Republican’s argument against impeachment, however, still needs some work.

President Trump says that the “only way” Democrats could possibly win in 2020 is to “bring out the artificial way of impeachment.” But in an exclusive interview with “Face the Nation” moderator Margaret Brennan, the president defended his leadership of the country, saying “you can’t impeach somebody for doing the best job of any president, in the history of our country, for the first two years.”

There are quite a few problems with this, but let’s focus on the two most obvious concerns.

The first is Trump’s apparent confusion about the nature of the process. In his mind, if a president is doing a great job, he or she “can’t” be impeached. In other words, he’s convinced that impeachment is reserved for bad and unaccomplished presidents.

That’s not how any of this works. Successful presidents can commit high crimes; woeful presidents can be innocent of any wrongdoing. We’re talking about two tracks that do not intersect.

The second is that Trump has an oddly misplaced confidence about how awesome his awesomeness has been.

Indeed, though this president is routinely eager to boast about his historic greatness, he tends to run into trouble when explaining what, specifically, has been so impressive about his tenure. In a New York Times interview last week, for example, he bragged, “You go down the list: Veterans Choice, V.A. Choice. They’ve been trying – as long as you’ve been writing they’ve been trying to get V.A. Choice…. Nobody thought it could be done.”

Actually, everyone thought it could be done – because V.A. Choice was created in 2014, under Barack Obama.

Also last week, while trying to highlight his purported accomplishments, Trump downplayed his failure to secure funding for a giant boarder wall. “Now they say, ‘It’s the wall,’ because I’ve accomplished practically everything else,” he insisted. “Look, I accomplished the military. I accomplished the tax cuts. I accomplished the regulation cuts. I accomplished so much.”

I’m still not at all sure what “I accomplished the military” meant, but regardless, the odd rhetoric is emblematic of a larger truth: Trump expects us to believe he’s racked up legendary victories, but it’s best not to ask him to list them.