Oh, for shame!

The remaining men vying for the Republican Party’s presidential nomination appear to have become embarrassments to the very people whose support they will need this fall when one of them square off against the Democratic Party presidential nominee.

What in the world has become of the process that selects major-party nominees seeking to become the most powerful officeholder in the whole world?

It has become a sideshow, a circus act, a schoolyard fight, a proverbial food fight.

Voters should demand better of the candidates. Then again, perhaps they secretly like what they’re hearing and seeing.

The Republican side of this carnival act has been particularly disgraceful. And that is coming from Republicans who’ve watched it.

GOP pollster Frank Luntz asked viewers who watched one of the Republican debates, the one in Detroit, to summarize what they saw. The Washington Post reported: “Sophomoric,” “embarrassment,” “disappointing,” “shameful,” “despicable,” “angering” and “schoolyard brawl” were some of the responses he received during a broadcast on Fox News Channel.

As one Republican told the Post — and this guy is a Ted Cruz supporter — the candidates need to be talking about ISIS and the “loss of freedom.”

Instead, he noted, they were engaging in the kind of talk one hears on junior high school playgrounds.

Who and/or what is the culprit?

Have social media become the communications vehicle of choice for too many Americans? We appear to be relying on Twitter feeds and Facebook posts to learn things — most of it irrelevant to actual policy — about these candidates.

Have their been too many of these Republican and Democratic primary debates? It might be that the candidates have run out of creative ways to argue the fine points of policy and have been left to resort to the kind of shameful name-calling and ridicule we’ve been hearing.

Do the candidates themselves deserve blame? Pundits keep talking about Donald J. Trump’s lack of depth and his mastery of media manipulation. Then there’s the belief among many that he is a barely closeted sexist, xenophobe and racist. The response from Ted Cruz to Trump’s insults has been, well, less than stellar as well.

The campaign should have been dignified. It has been everything except that.

These individuals are seeking to become commander in chief of the world’s greatest military machine. They want to become head of state of what many of us believe is the greatest nation ever created. They seek to lead a nation of 300-plus million citizens into a still-uncertain future.

And this is what we’re getting?