Washington, D.C., is the birthplace of countless clichés.

Such as, “At the end of the day,” we’re going to “kick the can down the road” while deciding whether to “walk and chew gum.”

The third — walking and gum-chewing — is the latest cliché du jour. It refers to lawmakers’ ability to investigate the president and legislate at the same time.

Donald Trump needs to learn that skill. Today, he demonstrated his inability to do what needs to be done for the benefit of the country he was elected to govern. He is angry with Democrats because they insist on getting at the truth behind questions about obstruction of justice, on the president’s personal finances and on whether he is covering up potential misdeeds.

Congressional Democratic leaders ventured to the White House today to meet with the president on infrastructure improvement, something Trump said he favors. Oh, but then House Speaker Nancy Pelosi said something out loud about believing that Trump is “covering up” possible illegal activity.

The president hit the ceiling. He walked into the meeting room, didn’t shake any hands, didn’t sit down at the conference table. He stood and spoke for about 3 minutes and said he was done working with congressional Democrats on any legislative matters.

Then he walked out. Senate Democratic Leader Charles Schumer said Trump’s actions this morning were “jaw dropping.” He said the president walked into the meeting room with no intention of working with Democrats on infrastructure.

This is what we’ve gotten? A president who once pledged to “unify” the country who now walks away from any possible major legislative effort because he is angry at Democrats who are keeping faith with their constitutional mandate?

I remain opposed to impeaching this guy because impeachment — at this moment — likely will not result in his removal from office. House Democrats would impeach Trump; Senate Republicans do not appear likely to convict him.

However, Donald Trump’s continued petulance and the chaos that results from legitimate questions, though, is giving me serious concerns about whether impeachment is inevitable.