Opinion writer

Republican presidential candidates at the first prime-time presidential debate last month. (Scott Olson/Getty Images)

With the excepting of Sen. Ted Cruz (R-Tex.), the campaign’s Eddie Haskell who fawns over Donald Trump, and Ohio Gov. John Kasich, who has tried to steer clear of him, most every contender in the GOP presidential field has landed a blow or two against Trump.

They, collectively, have rebuked him for misogyny, racism, xenophobia, ignorance, arrogance, inconsistency and more. Pundits obsessed with meaningless national polls are convinced this is not working, but in fact each candidate in his or her way is building the case against Trump. They are working to limit his appeal and to throw him off his game.

Sure enough, by week’s end he was hitting potholes. He insulted Carly Fiorina’s appearance and denied doing it — to the eye-rolling of the media and opponents. He eventually admitted he made the remark in  the context of being an “entertainer,” raising the question whether he is running for commander in chief or creating a reality show.

He bombed in a speech to a pro-Ukraine conference. The Hill reported:

Donald Trump delivered an address at a pro-Ukraine conference on Friday, calling President Obama “not strong” and saying Russian President Vladimir Putin “does not respect our president.”

More notable than what he said, however, was the way he said it.

Giving his speech via satellite feed, Trump spoke slowly, put heightened emphasis on his words and took long pauses between each sentence, evidently under the impression that he had to wait for translators to interpret his remarks to the audience.

“You need not wait for any translation,” one of the conference moderators said at one point.

And then there was his recycled 2013 tweet on 9/11, which chose the anniversary of the deaths of 3000 Americans to lash out at “losers” and “haters.” (“I would like to extend my best wishes to all, even the haters and losers, on this special date, September 11th.”) What a piece of work he is. (It’s not a “special” day like a birthday; it is a solemn remembrance and opportunity to reflect on the sacrifices of fellow Americans.)

At Wednesday’s debate, any number of opponents can lift the tone of the discussion, reject the politics of hate and insults and continue to present a contrast between Trump’s bombastic approach and serious, humane governance to fix what is wrong in the country.

Jeb Bush, as he has begun to do, should amplify the difference between his responsible ideas on immigration, government reform and taxes with Trump’s fly-by-the-seat-of-the-pants, contradictory declarations. Is Trump a liberal who wants to raise taxes or a conservative who thinks government is too big already?

From Ben Carson we can expect a stylistic contrast: The soft-spoken, gentle, pious doctor vs. the mogul who reduces everything to appearances and money. Really, could voters be proud of casting their vote for a billionaire devoid of redeeming personal characteristics?

Then there is Kasich. Rather than duck a fight, Kasich would be wise to show off his blue-collar, common man background and concern for those “living in the shadows.” Trumps cruelly calls them “losers”; Kasich should give him his speech on empathy reminding him that these are fellow Americans.

New Jersey Gov. Chris Christie, one of the funnier and more incisive candidates, can demonstrate that leadership is not about ordering people about, but working collaboratively to accomplish things, as he did in a blue state, on issues like education and entitlement reform. Christie has also demonstrated prowess with regard to foreign policy and can challenge Trump. After all, we don’t make “America great again” just by giving a speech. Until recently Trump did not want to rip up the Iran deal, just “police” it. Is that a recipe for making America great? What about preserving the NSA or Guantanamo?

Sen. Marco Rubio (R-Fla.) is running a hopeful campaign based on creating opportunity in the 21st century. He should not be afraid to remind us that Trump, 69, is a 20th-century billionaire who inherited his wealth. No wonder Trump advocated measures like protectionism and tax hikes. No skin off his nose.

Fiorina may be best positioned to show up Trump. Both because she is a woman and because she is verbally adept, she is ideally situated to call out his disrespectful, nasty rhetoric and disdain for women. Moreover, her ongoing attack against cronyism is the perfect issue on which to skewer Trump, who brags about his buying politicians. For him, getting rich is about manipulating government to his ends, the exact arrangement conservative reformers want to end.

We don’t know who will choose to engage Trump most directly. But in providing an informed, rational and detailed plan for governance Trump’s competitors can make the case: They are ready to lead a great country and he is, as he admitted, an entertainer with a flair for self-promotion. For them it is all about the country; for Trump it is solely about Trump.