Less than nine months into Donald Trump's presidency, one of the most extraordinary warnings about his behavior wasn't coming from Democrats, liberal activists or Trump's political opponents.
It came from one of the most powerful Republicans responsible for overseeing American foreign policy.
Sen. Bob Corker of Tennessee, chairman of the Senate Foreign Relations Committee, publicly described Trump's White House as an “adult day care center” and warned that the president's behavior could put the United States “on the path to World War III.”
The remarkable confrontation unfolded on October 8, 2017, after Trump launched a series of personal attacks against Corker on Twitter.
What began as another presidential social-media feud quickly became something much more serious: a senior Republican senator publicly questioning the judgment of a Republican president who controlled America's nuclear arsenal.
Trump Goes After a Republican Senator
Corker had recently announced that he would not seek reelection in 2018.
Trump responded that Sunday morning by claiming Corker had “begged” for Trump's endorsement, that Trump had refused him and that Corker subsequently decided not to run.
Trump also claimed Corker had wanted to become secretary of state and blamed him for the Iran nuclear agreement negotiated during the Obama administration.
He finished by predicting Corker would become a “negative voice” standing in the way of the Trump agenda.
Corker's office disputed Trump's account.
His chief of staff, Todd Womack, said Trump had actually called Corker days earlier, asked him to reconsider his retirement and told him he would endorse him if he ran again.
Trump's claim that Corker was responsible for the Iran nuclear agreement was also misleading. Corker had opposed the agreement and voted against it. His legislation established a process allowing Congress to review the deal rather than creating or approving the agreement itself.
Then Corker responded personally.
“Someone Obviously Missed Their Shift”
Corker's reply instantly became one of the most memorable Republican criticisms of Trump's first term:
“It's a shame the White House has become an adult day care center. Someone obviously missed their shift this morning.”
It would have been remarkable coming from virtually any Republican senator.
Coming from Corker made it considerably more significant.
He wasn't an obscure backbencher.
As chairman of the Senate Foreign Relations Committee, Corker occupied one of Congress' most important foreign-policy positions.
He had also previously been friendly with Trump.
Corker supported Trump during the 2016 campaign, advised him on foreign policy and was considered as a potential vice-presidential running mate and later as a possible secretary of state.
This wasn't a lifelong Trump opponent attacking the president.
It was a former ally.
And Corker wasn't finished.
“On the Path to World War III”
Later that day, Corker spoke extensively with The New York Times.
His criticism became considerably more serious.
Corker said Trump behaved as though the presidency were still a television program, comparing his conduct to Trump's former reality show The Apprentice.
But Corker's greatest concern involved foreign policy.
Trump had spent much of 2017 exchanging increasingly threatening rhetoric with North Korean leader Kim Jong Un as North Korea accelerated its nuclear and ballistic-missile programs.
Trump had threatened North Korea with “fire and fury.”
He had publicly referred to Kim as “Little Rocket Man.”
And only the day before Corker's comments, Trump had written that previous American presidents had unsuccessfully negotiated with North Korea for decades before declaring:
“Sorry, but only one thing will work!”
Against that backdrop, the chairman of the Senate Foreign Relations Committee issued an extraordinary warning.
Corker said Trump's threats toward other countries could put America “on the path to World War III.”
He also said that Trump concerned him and suggested that many other Republican senators shared those concerns privately.
According to Corker, senior administration officials including Secretary of State Rex Tillerson, Defense Secretary James Mattis and White House Chief of Staff John Kelly played an important role in restraining the president.
Corker had said only days earlier that those officials were helping “separate our country from chaos.”
This Wasn't Coming From Democrats
That distinction is what made October 8, 2017 so remarkable.
Democrats criticizing Trump was expected.
Corker was different.
He was a conservative Republican senator from Tennessee.
He chaired the committee responsible for overseeing American foreign policy.
He had worked with Trump.
He had advised Trump.
He had been considered for a position in Trump's administration.
And now he was publicly suggesting that senior officials surrounding the president were necessary to prevent chaos—and warning that Trump's behavior could contribute to a global military conflict.
Corker's retirement announcement also changed the political equation.
Because he no longer needed to win a Republican primary or seek Trump's endorsement, Corker had considerably less political incentive to remain silent.
The dispute exposed something that was often discussed privately during Trump's first year but rarely expressed so directly by senior members of his own party.
Some Republicans were deeply worried about the president.
Corker was simply willing to say it publicly.
A Warning From Inside Trump's Own Party
Looking back, the exchange remains one of the strangest episodes of Trump's first year in office.
The president of the United States spent a Sunday morning attacking the Republican chairman of the Senate Foreign Relations Committee.
The Republican chairman responded by comparing Trump's White House to a day care center.
Hours later, that same senator warned that Trump's behavior could lead the country toward World War III.
There were legitimate policy disagreements behind the feud—North Korea, Iran, taxes and America's broader foreign policy.
But October 8 went far beyond an ordinary disagreement over legislation.
It became a public argument about presidential judgment.
And perhaps the most significant part wasn't Corker's insult.
It was who delivered it.
Nine months into Donald Trump's presidency, a Republican senator who had once supported him and who chaired the committee overseeing American foreign policy was publicly telling the country that people inside the White House were trying to contain the president.
The phrase “adult day care center” became the headline.
But Corker's warning about what could happen if that containment failed was considerably more serious:
World War III.