In the spring of 2016, Donald Trump and Mitch McConnell, the Senate
Majority Leader, were both backstage at a National Rifle Association
conference in Louisville, Kentucky. The two men are political opposites.
McConnell is a poor orator but a gifted Senate tactician. He plays the
long game. Trump is a great showman but barely knows the basics of the
constitutional system. He improvises. In Louisville, McConnell noticed
that Trump, who was by then the presumptive Republican Presidential
nominee, was holding pages of prepared remarks in his hand. “I see you
have a script,” McConnell said, according to a former adviser who heard
the story from the Majority Leader. “Put me in the category of supporting that.”

“I hate it,” Trump said.

“But this is what you should be doing,” McConnell told him.

Until this week, the relationship between Trump and McConnell was one of
the less fraught ones among senior Republicans in Washington. Unlike
Paul Ryan, the Speaker of the House, who held out from endorsing Trump
for months last year and who has occasionally spoken
out—gingerly—against Trump’s worst excesses, McConnell has always viewed
Trump with a calculating eye. He had two priorities in 2016: to hold the
Republican majority in the Senate, and to help elect a Republican
President who would get to name a Supreme Court Justice for the seat
that he had refused to allow President Obama to fill. No matter how deep
Trump’s flaws, McConnell believed that antagonizing him would hurt those
twin goals. He supported Trump when he won the Republican nomination,
and he has rarely criticized him in public since.

“McConnell was extremely pragmatic about the relationship,” the former
McConnell adviser told me. “He never said anything if it wasn’t in the
interest of him, or his party’s interest, to say it. He didn’t want to
create any intra-party feud that could hurt his members.”

Last year, McConnell cared less about anti-Trump conservatives than he
did about Republicans such as Roy Blunt, the Missouri senator who was
facing a tough reëlection fight in a state where Trump was extremely
popular. “It wouldn’t have helped Blunt if McConnell was out there
trashing Trump,” the former adviser said—McConnell saved any rebukes for
personal conversations with Trump. “That’s the way the relationship
looked up until this week.”

What happened this week is that when Trump wasn’t busy threatening North
Korea, he was busy threatening McConnell. The attacks were provoked by a speech McConnell delivered on Monday in Kentucky, in which
he said, “Our new President, of course, has not been in this line of
work before. I think he had excessive expectations about how quickly
things happen in the democratic process.” On Wednesday, Trump responded.
“Senator Mitch McConnell said I had ‘excessive expectations,’ but I
don’t think so,” he tweeted. “After 7 years of hearing Repeal & Replace,
why not done?”

Trump woke up on Thursday with McConnell still on his mind. “Can you
believe that Mitch McConnell, who has screamed Repeal & Replace for 7
years, couldn't get it done,” Trump tweeted, a few minutes before 7 A.M.“Must Repeal & Replace ObamaCare!” Later in the day, he tweeted a
slightly more encouraging note: “Mitch, get back to work and put Repeal
& Replace, Tax Reform & Cuts and a great Infrastructure Bill on my desk
for signing. You can do it!”

Also on Thursday, reporters asked Trump if he wanted McConnell to step
down as Majority Leader. His answer was coy. “If he doesn’t get repeal
and replace done, and if he doesn’t get taxes done—meaning cuts and
reform—and if he doesn’t get a very easy one to get
done—infrastructure—if he doesn’t get them done, then you can ask me
that question,” Trump said.

Disagreements between a Senate Majority Leader and a President of the
same party are not a Trump-era innovation. They have a long history.
“They used to say that the best situation was to be the Majority Leader
with a President from the other party,” Donald Ritchie, a former
historian of the United States Senate, told me. “Majority Leaders are
expected to go to bat for the President even when it’s not in the best
interest of their party.”

Ritchie pointed to the relationship between John F. Kennedy and Majority
Leader Mike Mansfield, a fellow-Democrat. “He was criticized as not
being strong enough at getting Kennedy’s program through,” Ritchie said.
Nixon, too, had trouble with a member of his own party: Hugh Scott.
“Scott eventually supported impeachment and conviction of Nixon,”
Ritchie said. More recently, George W. Bush pushed for Trent Lott to
resign as Majority Leader after Lott said that the country would have
been better off if Strom Thurmond, who ran for President as a
segregationist, had won the election of 1948.

Still, Republicans in Washington were distraught at Trump’s attacks on
McConnell this week. When political heavyweights get into a public
fight, their aides generally try to play down the rift when talking to
reporters. But people close to McConnell whom I talked to didn’t play
anything down. “I think this is a different moment,” the former
McConnell adviser said. “I’m not saying it’s going to define the
relationship or persist, but it is different and it should be
acknowledged as such. McConnell is not a shrinking violet. He very
jealously guards the prerogatives of the Senate.”

Scott Jennings, a former senior adviser to McConnell, noted that Trump
this week wasn’t talking about the three Republicans senators—Lisa
Murkowski, John McCain, and Susan Collins—whose votes doomed the Party’s latest effort to repeal Obamacare. “Two of them were personally insulted
by the President,” Jennings said, referring to McCain and Murkowski, whom
Trump has attacked in the past. “And the other one is far more liberal
than the rest of the conference.” Jennings added, “Is Mitch McConnell to
blame for the personal relationships of Donald Trump and Murkowski and
McCain? I don’t think so.”

Jennings, like many of McConnell’s supporters, was mystified by Trump’s
lack of gratitude toward the senator, for his support during the
campaign and for the Supreme Court seat that he delivered. “Their
relationship is rooted in one thing,” he said. “McConnell kept open the
Scalia seat, which likely delivered the Presidency to Donald Trump.”
Putting Neil Gorsuch on the Supreme Court, Jennings said, “is Trump’s
only legislative achievement.” He added, “While a lot of Republicans were having mood swings about Trump during the campaign, McConnell stayed the course.”

Some Republican senators have also come to McConnell’s defense.
McConnell “has been the best leader we’ve had in my time in the Senate,
through very tough challenges,” Orrin Hatch, of Utah, tweeted on
Thursday. “I fully support him.”

Could Trump’s attacks on McConnell mark some kind of a turning point?
Sometimes, a dispute between a President and a Majority Leader can rock
a Presidency. In 1944, President Roosevelt, a New Yorker with a sense of
showmanship, and Majority Leader Alben Barkley, a Kentuckian who was
often criticized for not standing up to F.D.R., clashed over a tax bill
passed by Congress and vetoed by the President. In his veto
message—Twitter had not yet come along—Roosevelt said that the bill was
“not for the needy, but for the greedy.” Barkley considered this such a
personal affront that he immediately resigned as Majority Leader. The
Senate rose up against F.D.R., overriding his veto and reinstalling
Barkley. One senator, Elbert Thomas, of Utah, remarked that before
the incident, Barkley “spoke to us for the President,” but since then,
“he speaks for us, to the President.”

In 2007, McConnell himself told this history in a speech on the Senate
floor. “The Majority Leader and the President mended the breach soon after, and continued to work together,” McConnell, who has long had a
picture of Barkley hanging above his desk in his Capitol office, said.
“But you could say their relationship was never again the same.”