Hillary Clinton's surrogates have struggled this week to live up to the campaign's boast that it goes high when Donald Trump and his team go low.

The Clinton team often brags that it is running a genuinely optimistic campaign; one that offers a positive alternative to Trump's signature bluster.

The Democratic nominee and her spokespersons also tend to quote First Lady Michelle Obama, who said this year at the Democratic National Convention in Philadelphia, "our motto is, when they go low, we go high."

This week, however, some Clinton surrogates failed to take that high road.

On Friday, Rep. Debbie Wasserman Schultz, D-Fla., joked at a campaign rally that no one in the world could make Trump physically attractive.

"A couple more thoughts about Donald Trump's appearance," the Clinton surrogate said at a rally in Coral Springs, Fla. "I'm going to keep those thoughts to myself for two reasons."

"First of all, you could put all the fashion experts and stylists in the world to work for Donald Trump, and he still couldn't win a beauty contest," the former chair of the Democratic National Committee said. "Wait, wait. want you to understand what I mean. Not in this universe, because you can't fix ugly when it's on the inside. Am I right?"

She added that the second reason she wouldn't comment on the GOP nominee's appearance — although she already had — is because she was raised with "class."

On Wednesday, in response to reports that Trump mistreated former model Alicia Machado in the mid-1990s when she put on weight as a Miss Universe contestant, Sen. Claire McCaskill, D-Mo., suggested that the Republican candidate had a weight problem of his own.

"The [Democratic] women Senators have talked & we're concerned about Donald's weight. Campaign stress? We think a public daily weigh-in is called for," the Clinton supporter said on social media.

On Monday, former Vermont Gov. Howard Dean suggested that Trump was high on cocaine during the first presidential debate, which was held at Hofstra University in New York.

"Notice Trump sniffing all the time. Coke user?" the Clinton surrogate said, referring to Trump's sniffing during the debate.

It took Dean four days to walk back the comment.

"I apologize for using innuendo," he told MSNBC's Stephanie Ruhle on Friday. "I don't think it's a good thing to do. I don't think it's the right thing to do. This entire campaign has been debased by innuendo."

Trump, for his part, has spent much of this week fighting claims he mistreated Machado. He has not denied that he reprimanded the former Miss Universe for her weight gain. Instead, Trump has responded to the news cycle by attacking her character.

The GOP nominee for president encouraged his Twitter followers Friday morning to check out her "sex tape," an apparent reference to a non-explicit scene she appeared in for the Spanish-language reality-TV show "La Granja."

In one episode, "the former beauty queen supposedly had sex with a fellow cast member," the Daily Beast reported.

The Daily Beast also noted this week that, contrary to rumors circulated on social media, Machado is neither a porn star, nor has she starred in any explicit, X-rated material.