WASHINGTON – Republican Sen. Mitt Romney said the conduct by President Donald Trump and his campaign outlined in special counsel Robert Mueller's report left him "sickened" and "appalled" — marking one of the first prominent Republicans to make such critical comments of the president in the aftermath of the blockbuster investigation.

Romney, R-Utah, offered his reaction on Twitter after reading the full 448-page report, writing that while he was pleased that Mueller concluded that the Trump campaign did not conspire with Russia to interfere with the 2016 election, the level of lies and dishonesty outlined in the report left him with the realization of "how far we have strayed from the aspirations and principles out the founders."

"I am sickened and the extent and pervasiveness of dishonesty and misdirection by individuals in the highest office of the land, including the President," wrote Romney, a one-time presidential nominee who has repeatedly clashed with Trump over the years. "I am also appalled that, among other things," fellow citizens working in a campaign for the president welcomed help from Russia — including information that had been illegally obtained."

The highly anticipated report, which was released Thursday, revealed what news outlets many have reported for years: the behind-the-scenes chaos within the White House.

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When it came to the Trump campaign's contacts with Russia, some aides “lied” to the special counsel and Congress about their interactions. "Those lies materially impaired the investigation of Russian election interference," the report stated. While noting that the campaign expected to "benefit" from Russia's efforts, Mueller's office did not find evidence that their conduct amounted to a crime.

The report also suggests that, in some instances, Trump's aides were attempting to protect the president by not carrying out his requests. The murkiness around their motivations – and his – are a central reason why it was difficult for the special counsel's team to determine whether the president attempted to obstruct justice.

"The president's efforts to influence the investigation were mostly unsuccessful, but that is largely because the persons who surrounded the president declined to carry out orders or accede to his requests,” Mueller wrote in the report.

Those people included then-White House Counsel Don McGahn. Trump, according to the report, ordered that McGahn make a call to Deputy Attorney General Rod Rosenstein and have Mueller fired, which McGahn told Mueller he refused to do and instead, threatened to resign.

When the episode leaked to the press, Trump denied it ever happened and dubbed it "fake"

On the report as a whole, Romney said it was "good news" that Mueller did not establish enough evidence to charge the president with a crime, noting the very difficult effects that would have had on the country, but the evidence noted was troubling.

He ended on a somber note, "reading the report is a sobering revelation of how far we have strayed from the aspirations and principles of the founders."

Contributing: Gregory Korte and John Fritze