In a statement Wednesday morning, Secretary of State Rex Tillerson reaffirmed his commitment to President Trump's agenda, addressing what he called "erroneous rumors" in news reports this morning.

As prominent Republicans fret over Donald Trump's"unpresidential" behavior, that broad and undefined sentiment was aptly summed up by GOP Sen. Bob Corker of Tennessee, who lamented that the White House has become "an adult day care center."

In response to a fresh outburst from the president, Mr. Corker added mischievously, "Someone obviously missed their shift this morning."


The obvious reference is to the impression that White House Chief of Staff John F. Kelly is obliged almost daily to save the president from his own impulsive and habitually childish comments, which often imperil national security.

The Republican chairman of the Foreign Relations Committee, who recently announced he will not seek re-election next year, made clear that he believes Mr. Trump has neither "the stability nor some of the competence that he needs to demonstrate in order to be successful."

Not surprisingly, Mr. Corker, once mentioned as a possible secretary of state in the Trump Cabinet, invited a slashing tweet from the president. He charged that the Tennessean in 2016 had "begged" him for his endorsement for the Senate but hadn't gotten it, despite endorsing Mr. Trump for the Oval Office. And now, Mr. Trump wrote, Mr. Corker "didn't have the guts" to seek re-election.

The GOP senator's crack about the White House day care center followed speculation that Mr. Kelly, Secretary of Defense James Mattis and National Security Adviser H.R. McMaster, all former military generals, were aboard as seasoned veterans to corral Mr. Trump's erratic excesses.

Secretary of State Rex Tillerson, a longtime CEO of the ExxonMobil oil dynasty, was likewise viewed by Trump critics as part of the sensible coterie that monitors the president's erratic impulses. That was so especially in the hazardous arena of foreign policy, despite Mr. Tillerson's own paucity of experience in the field.

Neither man knew each other at the time Mr. Trump chose Mr. Tillerson. The president offered the job on the suggestion of former Secretary of Defense Robert Gates, presumably in part on because Mr. Tillerson once shared a table with Russian President Vladimir Putin at a Moscow dinner.

Subsequently, in an interview with The New York Times, Mr. Corker broadened his concern over Mr. Trump, saying he feared the president was setting the United States "on a path to World War III" with his taunts against North Korean dictator Kim Jong Un and suggestions that he might "destroy" the communist dictator and his country in a nuclear attack or exchange.

"He concerns me," Mr. Corker said of Mr. Trump. "He would have to concern anyone who cares about our nation. I know for a fact that every single day in the White House, it's a situation of (his senior watchers) trying to contain him." Mr. Corker told reporters that Messrs. Tillerson, Mattis and Kelly are "people that help separate our country from chaos."

Mr. Corker also told The Times: "Look, except for a few people, the vast majority of our (Senate Republican) caucus understand what we're dealing with here ... the volatility that we're dealing with and the tremendous amount of work that it takes by people around (Mr. Trump) to keep him in the middle of the road."

Mr. Trump has been said to mention the so-called "madman theory" attributed to former President Richard Nixon, who believed that spreading the notion among foreign adversaries that he was unbalanced and out of control would oblige them to deal cautiously with him.

In the Constitution there is no stipulation that the Oval Office occupant behave in a "presidential" manner, however that may be defined. Failing to be presidential is not among the grounds for impeachment as an abuse of power that could lead Special Counsel Robert Mueller, investigating possible Trump collusion in the Russian meddling in the 2016 presidential election, to charge him. Nor presumably is it justification for the vice president and a majority of the Trump cabinet to declare the president unable to fulfill his duties of office under the 25th Amendment.

Yet there is a growing concern within the old Republican establishment that his loose-cannon quality of governance is politically and institutionally cataclysmic for the Grand Old Party. It guarantees a continuing state of internal discomfort and bewilderment as the Trump era stumbles and staggers on.

Jules Witcover's latest book is "The American Vice Presidency: From Irrelevance to Power," published by Smithsonian Books. You can respond to this column at