In his Republican National Convention speech, Senator Ted Cruz pointedly did not endorse Donald Trump. PHOTOGRAPH BY PHILIP MONTGOMERY FOR THE NEW YORKER

Give one thing to the Republicans: they can’t be boring even when they try to be. On Wednesday night here in Cleveland, the idea was to force fifteen thousand or so journalists, many of whom have spent the past couple of days immersed in the intricate details of “Melaniagate,” to write and talk about the Republican Party coming together to hail the Donald Trump–Mike Pence ticket. A speech by the Vice-Presidential nominee was meant to be the highlight of the night.

Sadly, nobody explained this plan to Ted Cruz, the senator from Texas who came a distant second in the G.O.P. primaries. Or, if it was explained to him, Cruz ignored it. Rather than endorsing Trump and Pence, he told the voters to “vote your conscience,” and was booed off the stage not long after a stern-faced Trump entered the back of the arena and made his way to a viewing box. So furious were some of Trump’s delegates and supporters that they reportedly screamed at Cruz’s wife, Heidi, as she left the Quicken Loans Arena.

Despite a brave effort by Newt Gingrich, the next speaker, to spin some of Cruz’s remarks in a more positive light for Trump, the flap inevitably hung in the air during Pence’s speech, which was actually pretty effective and earned him chants of “We like Mike,” as well as a lengthy ovation at the end, when his family joined him onstage. However, the applause couldn’t disguise the fact that Cruz had stolen the night. To his defenders in the Republican Party, and there were some afterward, he had acted as a principled conservative, refusing to compromise by embracing a figure who has defied Republican orthodoxy in numerous respects and is temperamentally unfit to be President. But to most of the attendees in Cleveland, Cruz was the boorish party guest who accepts an invitation then insults the host, throws up on the rug, and has to be shown the door. Speaking from the Convention floor, Chris Christie, a close Trump ally, said that Cruz had delivered an “awful, selfish speech” and had “showed himself tonight to not be a man of his word.”

Until Cruz’s appearance, the proceedings had been going pretty much as planned. After a bunch of no-name speakers provided testimonials to Trump early in the night, Scott Walker, another defeated primary candidate who has made clear his distaste for the New York billionaire, did everything that the Trump campaign could have asked of him, telling skeptical Republicans to suck it up and pull the lever. “America deserves better than Hillary Clinton,” Walker said. “And that, ladies and gentlemen, is why we need to support Donald Trump and Mike Pence to be the next President and Vice-President of the United States.” Walker went on to warn conservative Republicans not to vote for Gary Johnson, the Libertarian Party candidate, who is doing pretty well in the polls. “Let me be clear,” Walker said. “A vote for anyone other than Donald Trump in November is a vote for Hillary Clinton.”

Barely had Walker left the stage when Marco Rubio, who earlier this year described Trump as “a con artist,” appeared on the big screens that litter the arena. After saying that Clinton wasn’t fit to be President, he offered a list of policy reasons why voters should support Trump, which included the Supreme Court, the fight against Islamist extremism, and tax policy. “After a long and spirited primary, the time for fighting each other is over,” Rubio said. “It’s time to come together and fight for a new direction for America.”

Somewhere in the wings, presumably, Reince Preibus, the chairman of the Republican National Committee, was cheering. It has taken Preibus months to get most of the Republican establishment to accept Trump, and now all of his work appeared to be paying off. But then Cruz took the stage and, after offering the briefest of congratulations to Trump for winning the nomination, embarked on his monologue. Twenty minutes later, he hadn’t mentioned Trump’s name again.

The heckling appeared to start with the New York delegation, which is heavy with Trump supporters. Shouts of “Endorse Trump!” and “We want Trump!” spread around the hall. When Cruz said, “Vote your conscience, vote for candidates up and down the ticket who you trust to defend our freedom and to be faithful to the Constitution,” the shouts turned to catcalls. As he finished up and left the stage, the boos showered down on him as though he were a relief pitcher who had just blown a big lead.

Gingrich tried to recover the situation, suggesting that the crowd had misinterpreted Cruz. In this election, there was only one candidate who would uphold the Constitution, he said, and that meant that anyone who followed Cruz’s advice would support the Trump–Pence ticket. Gingrich’s ability to improvise on his feet was impressive, but it didn’t take away from the fact that Cruz had failed to endorse Trump and had used language that was redolent of the Never Trump movement.

When Pence spoke, he wisely avoided the Cruz controversy entirely, returning instead to the argument that Scott Walker had laid out earlier. “In the end, this election comes down to just two names on the ballot,” he said. “So let’s resolve here and now that Hillary Clinton will never become President of the United States.” But Pence didn’t confine his case to instrumentalism. “Donald Trump gets it,” he said. “He’s the genuine article. He is a doer in a game usually reserved for talkers. . . . He's his own man: distinctly American.” Presumably, these words were written for Pence by someone else, but they suited his clipped Midwestern diction, and he delivered them with apparent sincerity. “He’s tough. He perseveres,” Pence went on, still referring to Trump. “He has gone about as far as you can go in business, but he’s never turned his back on the working men and women who make this country grow.”

Some former students of Trump University would no doubt take issue with that statement. But Pence’s calm demeanor, his willingness to testify for Trump to his fellow-conservatives, and his jabs at Clinton and President Obama, which were delivered directly but in a non-hysterical manner, all helped to explain why Paul Manafort, Trump’s campaign manager, was so keen for Pence to be the Vice-Presidential pick. Based on this appearance, at least, Pence could prove to be an effective straight man and sidekick. For instance, instead of referring to Clinton as “Crooked Hillary,” as Trump does, he said that Americans were demanding change, and called her the “Secretary of the Status Quo.”

Trump, certainly, appeared to appreciate Pence’s effort. Appearing from stage right after the speech was done, he gave his running mate two thumbs up and an air kiss. A bit later, on Twitter, Trump tried to play down Cruz’s refusal to endorse him, while also making clear that he regarded it as treachery. “Wow, Ted Cruz got booed off the stage, didn’t honor the pledge!” Trump wrote. “I saw his speech two hours early but let him speak anyway. No big deal!”

But, of course, it was a big deal.