Former House speaker Newt Gingrich greets Donald Trump at a rally at the Sharonville Convention Center in Cincinnati on Wednesday. (Aaron P. Bernstein/Reuters)

SHARONVILLE, Ohio — Donald Trump wasn’t scheduled to take the stage here until 7 p.m. Wednesday. But by 6:30 p.m., the crowd on this sweaty summer night was growing noisy and restless, and launching into sudden sporadic chants about “crooked Hillary” as they packed together tightly.

Then someone spotted it: a fluff of salt-colored hair stage right. And a sudden and grumbling chant broke out, stretching the name of the night’s guest speaker with knowing affection.

“Neeeeeewt!” They bellowed. “Neeeeeewt! Neeeeeewt!”

Newt it was.

Newt Gingrich, former House speaker and now a finalist in the search for Donald Trump’s running mate, quickly stepped up to the lectern. While officially just making a friendly trip with Trump to this swing state, it was also an audition for the No. 2 spot — a chance to showcase his wares and see for himself whether he fits comfortably within Trump’s orbit.

Former House speaker Newt Gingrich is on Republican presidential candidate Donald Trump's short list of potential vice presidential candidates. Here's what you need to know about him. (Sarah Parnass,Danielle Kunitz,Osman Malik/The Washington Post)

His brief turn was telling. From the start, Gingrich played the role of party elder. It was a nod, perhaps, to how as the veep pick he might put an emphasis on lifting vulnerable GOP candidates this fall rather than solely playing the part of Trump booster.

“I know with all of my heart,” Gingrich told them with the tone of an insistent teacher, that they would “carry this state” not only for Trump but for Sen. Rob Portman of Ohio. The crowd, dotted with clumps of rowdy men and women in Trump gear, politely clapped as if to accept the request.

In response, Gingrich offered his signature look: the dropping of his chin and a narrowed-eye glare, very Trump-like.

Gingrich then touted his biography, “a former speaker of the House who knew a little about Washington.” But he framed himself as someone with populist instincts in spite of his years on Capitol Hill. It was similar to how Trump has framed his time as a big GOP donor: Yes, he was on the inside, but in his mind that only makes him better at calling out corruption at the highest levels.

Gingrich segued into a takedown of his enemies going back decades: the Clintons. Unfurling lines about the controversy over presumptive Democratic nominee Hillary Clinton’s use of a private email and servers, he painted Bill and Hillary Clinton as a couple that has for years evaded legal scrutiny, one day after the FBI director offered a scathing review of Clinton’s email practices but did not recommend prosecution. He called the FBI’s conclusion a “total sellout of the American system” and said Clinton has “total guilt.”

“Is there a single person here who believes that if you had done what Hillary Clinton had done that you would not be prosecuted?” Gingrich asked dramatically.

“No!” people yelled.

Gingrich said the Clinton email episode is reflective of a broader development in the country of “two Americas” — the “corrupt Washington of the old order” and “the rest of us.”

“I say to you, ‘Enough!’ " Gingrich said, running through a list of gripes with Democrats. “Enough of lying to us about a person who deliberately obstructed justice and under any rule of law would today be facing a jury, not an election.”

The not-so-subtle message to Trump: Gingrich is more than happy to play attack dog.

Gingrich closed by referencing his time as a history professor in Georgia, in essence making the point to Trump’s campaign that if picked, he would be able to add some historical depth and intellectual sheen to Trump’s already roiling critique. And he showed that he’s willing to poke his friends in service of the nominee.

“It’s about time that he get on the Trump bandwagon,” Gingrich said of Ohio Gov. John Kasich, who served with him for years in Congress but has been reluctant to endorse Trump after their bitter primary race.

Turning to other skeptics in the party, Gingrich said they should prepare for a different kind of Washington should Trump win. “This guy,” he said, “is going to kick over the table.”

Moments later, the churning guitar chords of “All Right Now” by Free began to play and Trump appeared, wrapping his arm around Gingrich and flashing a thumbs up as the Sharonville Convention Center roared for the main attraction.

Gingrich, 73, and Trump, 70 — both in dark suits and ties — looked out admiringly, with Gingrich raising his arm high up. Trump leaned in to whisper something to Gingrich as he departed and patted his shoulder.

Trump teased the prospect of picking Gingrich throughout his remarks. “I’m not saying anything and I’m not telling Newt anything. But I can tell you, in one form or another, Newt Gingrich will be involved with our government, okay," he said. "He’s tough.”

Trump kept looking over toward Gingrich throughout, pointing his finger as if he were prodding an older brother or college roommate, especially when he mentioned Gingrich’s praise of his own campaign and Gingrich's personal considerations.

“Newt’s going to get involved if I get approval from his wife,” Trump said, eyeing Gingrich as he said it.

Speaking at a rally in Cincinnati, Ohio, Republican presidential candidate Donald Trump said that former House speaker Newt Gingrich "is going to be involved with our government." Gingrich is on Trump's vice presidential short list, according to campaign associates. (Reuters)

Their rapport underscored how a Gingrich pick in many respects would be Trump selecting his alter ego — a combative and septuagenarian politician who naturally aligns with anti-establishment fervor and eschews message discipline.

Not every Republican loves the idea.

“Newt has loose-cannon tendencies which must appeal to Trump as the greatest loose cannon of all time,” said Mike Murphy, the veteran strategist who advised former Florida governor Jeb Bush’s super PAC during the primaries. “I’m not sure what Trump needs is more loose cannonism.”

Gingrich is one of several Republicans under review who have met with Trump in recent days, including Indiana Gov. Mike Pence and New Jersey Gov. Chris Christie. Sen. Bob Corker (Tenn.) was under consideration until Wednesday, when he bowed out of the running in an interview with The Washington Post.

Gingrich, who served as speaker from 1995 to 1999 and was the leader of the 1994 GOP House takeover, has been out of office for nearly two decades. He ran for president in 2012, when he found some success but ultimately was defeated by Mitt Romney. That bid presaged the kind of campaign that Trump would launch four years later: heavily based on television appearances, electric buzz from debates and clashes with moderators and the media, and allies expressing concern about the campaign's lack of ground organization.

Here in the suburbs of Cincinnati on Wednesday, Trump was initially slightly taken aback by the flurry of “Neeeeeewt” chants that popped up as he spoke for more than an hour. He playfully wondered aloud whether some people may be booing.

“Listen to these people, it’s like a football game,” Trump said. “Newt! Newt!” he added in the manner of a grunting fan.

“I don’t know. Newt, are they booing or are they saying Newt?” Trump asked, looking toward Gingrich off stage. “It’s one of those names, right? No, they love Newt. They do love Newt. We all love Newt. Newt gets it.”

“I’ll tell you one thing folks, I’m not saying it’s Newt, but if it’s Newt, nobody’s going to be beating him in those debates, that’s for sure, right? Nobody is beating our Newt in the debates.”

Touting his fundraising haul, Trump looked again over to Gingrich. “Did you hear that, Newt?”

Gingrich, who flew with Trump to Ohio and flew back with him to New York Wednesday night, joined him on the rope line as soaring Broadway tunes filled the room. Supporters lined up and waved markers at the men. Gingrich shook hands and signed a few autographs but kept a few steps behind Trump as the candidate slowly made his way.

The chants for Gingrich continued even there, and he was undoubtedly a star in his own right. But on this night, with a vice-presidential pick a possibility, he was careful to not be the shining one.