Donald Trump and his wife, Melania, and Ted Cruz and his wife, Heidi. (FROM LEFT: Carlos Osorio/Associated Press; Jim Watson/AFP/Getty Images)

Back in the fall, when Donald Trump dubbed Jeb Bush “low-energy,” Carlos Gimenez grew a little concerned. By last month, when Marco Rubio and Trump engaged in childish name-calling, the Republican mayor of Miami-Dade County thought the GOP presidential race had gotten “out of hand.” Now, after a ­tawdry week that has focused on the wives of Trump and Ted Cruz, Gimenez is certain that the race has moved totally “out of bounds.”

“Politics is a contact sport,” Gimenez said, “but there should be contact in other ways.”

Gimenez is watching with disgust, as are many Republicans across the country, as his party’s presidential race turns into a tabloid talk show. After a winter that featured anatomical insults, violent clashes at rallies, and fierce accusations of lying and dirty tricks, Republicans say the past week has been particularly dispiriting.

At a moment when the party had hoped to turn its attention to a general-election matchup against Hillary Clinton, Repub­licans were instead caught in an uncomfortable back-and-forth over allegations of adultery and jabs at the physical appearance of the wives of Trump and Cruz.

That dispute took on renewed vigor Sunday, when the two candidates went at it again on the morning shows.

Republican frontrunners Ted Cruz and Donald Trump exchange jabs on Sunday talkshows over a National Enquirer article alleging extramarital affairs by Cruz and a near nude photo of Trump's wife distributed by an anti-Trump super PAC. (The Washington Post)

On ABC’s “This Week With George Stephanopoulos,” Trump accused Cruz of helping to orchestrate an attack on his wife from the anti-Trump Make America Awesome super PAC, which placed an ad on social media featuring a racy photograph of Trump’s wife, Melania, from an old magazine photo shoot.

“Don’t forget, I call him ‘Lying Ted.’ I call him that because nobody that I’ve known — I’ve known a lot tougher people over the years in business, but I’ve never known anybody that lied like Ted Cruz,” Trump said.

Trump has offered no evidence that Cruz worked in concert with the super PAC; such collaboration would be a federal crime.

Appearing on “Fox News Sunday,” Cruz denied playing any role in the ad and denounced it. He slammed Trump for retaliating by retweeting side-by-side photos of his wife, Heidi, and Melania meant to disparage Heidi’s appearance.

“It is inappropriate, it is wrong, it is frankly disgusting to see a candidate attacking the spouse of another,” Cruz said.

Cruz has also accused Trump and his associates of pushing a false story to the National Enquirer about him having extramarital affairs. Trump has denied playing any part in the story. Cruz has forcefully denied the Enquirer story.

The other Republican in the race, Ohio Gov. John Kasich, said in an interview that his party is verging on a dangerous point of no return.

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“You never want to resort to family,” Kasich said. “That’s a horrible thing, and we cannot cross this threshold in this election, because once you cross it, there’s never coming back.”

The luridness has weighed not only on Republican elected officials but on voters as well. In a recent CBS News-New York Times poll, 60 percent of Republican primary voters said the campaign has made them mostly embarrassed for the party rather than mostly proud. The survey was conducted before the Cruz-Trump fight involving their spouses erupted.

On the campaign trail Friday in Green Bay, Wis., Cruz ordered fried fish for Heidi and their young daughters, pausing to shake hands and pose for selfies. But around him, voters were more focused on the unsavory turn the campaign had taken — which they blamed mostly on Trump.

“That’s junior high school stuff,” said Chris Cary, 53, a Web programmer who backs Cruz. “We should be talking about ISIS. We should be talking about the loss of our freedoms.”

Christopher Handler, 60, a painter at Lambeau Field, concurred, saying, “I don’t like to see the wives getting involved.”

Trump has been at the center of many of the campaign’s most vitriolic moments. The real estate mogul has insulted Carly Fiorina’s looks, questioned Ben Carson’s religion, and endlessly mocked Bush, Rubio and Cruz.

His latest fight with Cruz began Tuesday night, hours after the terrorist attacks in Brussels, when Trump tweeted: “Lyin’ Ted Cruz just used a picture of Melania from a G.Q. shoot in his ad. Be careful, Lyin’ Ted, or I will spill the beans on your wife!”

Gimenez, who publicly backed Bush, then Rubio and now no one, said such antics mean that the candidates are missing an opportunity to talk about more pressing matters. “So much of this stuff is childish,” he said.

Jennifer Horn, the chair of the New Hampshire Republican Party, is similarly troubled. “I think it is imperative that our candidates focus on the positive and optimistic message of conservatism if we are going to beat Clinton,” said Horn, who is not publicly backing a candidate.

Frank Luntz, a Republican pollster who regularly conducts focus groups to capture voter sentiment, said the level of worry within the party escalated dramatically after consecutive contentious debates in Houston on Feb. 25 and in Detroit on March 3.

“They are frustrated because they want their candidate to defeat Hillary Clinton, and they think the tone and topics won't succeed at that mission,” Luntz said.

After the Detroit debate, Luntz asked his focus group participants to sum up the evening in a word or phrase.

“Sophomoric,” “embarrassment,” “disappointing,” “shameful,” “despicable,” “angering” and “schoolyard brawl” were some of the responses he received during a broadcast on Fox News Channel.

In that debate, Trump, Cruz and Rubio traded petty insults and spoke condescendingly to one another. At one point, Trump brought up Rubio’s implications about his manhood to assure the audience there was “no problem” in that area.

A week earlier in Houston, Rubio ambushed Trump, unleashing attacks on several fronts after largely steering clear of the mogul for months. The next day, Rubio insulted Trump’s spelling errors, called him a “con artist” and joked that his rival may have wet himself during the debate. Trump returned fire, calling Rubio a “low-life” and a “nervous basket case.”

Kasich has tried to avoid the kind of fights that have consumed Trump and Cruz and which seemed to do Rubio, Bush and others more harm than good.

“Some people call me boring as a result,” Kasich said. “Well, if I’m boring, then good. I accept it.”

But taking the high road has yielded Kasich few political rewards. He sits a distant third behind Trump and Cruz in the delegate count. The only state he has won is his home state of Ohio.

Republicans concerned about the tenor of the campaign say that it is not too late to reset to a more civil tone. The field showed it can put aside personal attacks for a mostly cordial policy discussion at a recent debate in Miami.

But every time the campaign seems to move toward higher ground, it slips back into the gutter. And party members worry that the longer the harsh attacks predominate, the more difficult the healing process will become.

“This is like smoking,” Luntz said. “If you stop smoking, your body will repair itself.”

David Weigel in Green Bay, Wis., contributed to this report.