There are awkward moments, and then there are events such as what we witnessed today at the White House.

German Chancellor Angela Merkel paid a visit to Donald J. Trump. The two of them posed for cameras. Someone yelled out about a handshake. The president didn’t offer his hand. The chancellor looked puzzled after she had asked for one from her colleague and host.

Hmmm.

Strange moment, indeed.

Hockey players shake hands after beating each other up during their matches; Little Leaguers shake hands after games, sometimes cheering “Two, four, six, eight, who do we appreciate … ?”

Gentlemen extend a hand to ladies. It can be interpreted, perhaps, as a game. Trump, though, doesn’t play games … apparently.

I heard about this moment and my thoughts flashed back immediately to something similar that occurred in 1990 right here in Texas.

Republican gubernatorial nominee Clayton Williams was running against Democratic nominee Ann Richards. The two of them were fighting each other viciously.

Then they appeared together at an event. I cannot remember its precise nature. Afterward, with candidates sharing a head table, Richards extended her hand to Williams — who promptly refused to take it; he called her a “liar.” He walked away.

Commentators said at the time Williams committed a cardinal sin among gentlemanly Texans by refusing to take a lady’s hand and it likely helped contribute to Richards defeating Williams in that year’s election for Texas governor.

The president of the United States need not worry about German voters should he decide to seek re-election in 2020.

But, geez, Mr. President. Show some manners.