RICHMOND, Ky. — President Trump’s quest to help Republican midterm candidates has taken him this month to an airplane hangar in a far-flung Nevada county that he won with 73 percent of votes, a fairgrounds building in rural Ohio that could only hold 3,000 and an 8,000-capacity college arena in Kentucky — located about 25 miles south of Lexington, where Air Force One landed and where larger venues are located.

As the president campaigns, he has mostly avoided the suburban areas that strategists say will be key to deciding the midterms — and where he is often less popular and runs the risk of energizing Democrats or hurting Republican candidates who have tried to distance themselves from him. Over the past few weeks, he has focused heavily on more rural areas where he is especially popular and where his presence can encourage the base voters Republican candidates need.

Of the 27 midterm rallies Trump has held this year, more than three-quarters were held in counties that he won in 2016 by an average of 59.5 percent. The few times that he has ventured to counties that Democrat Hillary Clinton won, those places are nearly always surrounded on all sides by counties that he won. And more than a third of the rallies were in or near the Appalachian Mountains, where his popularity remains high.

Those areas, and the snug event spaces he finds there, have become Trump’s comfort zone, and also a sign of how convinced he remains that his most loyal supporters can drive a victory in 2018 as they did in 2016. (A rare departure will occur Monday night, when Trump will attempt to fill his largest venue in nearly two years: The Toyota Center in the heart of Houston can hold 19,000 and is located in a county that Clinton won in 2016.)

“Most people assumed he would go to Lexington, to a big venue like Rupp Arena — and, no doubt, President Trump would fill up 24,000 in Rupp,” Rep. Garland “Andy” Barr (R-Ky.) told the rally crowd gathered Oct. 13 at Eastern Kentucky University. “But when I thought about where the president would want to go, I thought . . . of the people of Madison County, who nearly two years ago delivered a huge victory for Donald Trump, who carried this county by a whopping 32 percentage points.”

Trump’s decision to visit Richmond — which he said was a trip he “normally” wouldn’t make — delighted those who live in the area. As his motorcade snarled traffic, two women stopped into a local craft store to wait out the backup, and one exclaimed to the other: “That’s the coolest traffic I’ve ever been in!”

During an Oct. 20 rally in Elko, Nev., President Trump said he created a new hashtag: “Democrats produce mobs, Republicans produce jobs.” (The Washington Post)

“He understands that America really is in the places that are not the most heavily populated, that are the most working-class — that’s pretty much what he goes for, and that’s why he got elected,” said Aaron Pramuk, 33, an engineer who lives in Richmond and came to the rally with his roommate. The two didn’t get inside but watched Trump’s remarks on a video screen outside with hundreds of others, as a rogue vendor circulated through the crowd selling $10 MAGA hats and cans of Bud Light.

Trump’s rallies have played a huge role in the president’s image-making.

The campaign frequently issues tickets to thousands more than an event space can seat, guaranteeing a full crowd and ensuring that the president will be able to brag that he had to turn people away — a number that, like the number who get in, Trump often wildly exaggerates.

Although Trump regularly claims that tens of thousands of supporters flock to see him, the average capacity of his rally venues this year is about 8,000. The largest venue so far has been the Charleston Civic Center in West Virginia, which can hold 13,500 — although Trump was unable to fill it in late August.

The largest rally that Trump has ever held — according to counts by independent officials — was at a stadium in Mobile, Ala., in August 2015. Estimates for that crowd range from 20,000 to 30,000, although Trump has claimed there were 49,000 people there.

One official said that the campaign’s favorite venues are Rust Belt hockey arenas because of their modest size and proximity to the sorts of voters who want to attend Trump rallies. Of the 27 midterm rallies, 10 have been held at hockey arenas and one at a former hockey arena.

Trump’s Monday event in Texas was previewed more than seven weeks ago, when the president promised on Twitter that he would book “the biggest stadium in Texas we can find” for a rally with Sen. Ted Cruz (R-Tex). Some advisers have told The Washington Post that they tried to discourage the president from going, as they expect Cruz can win the race without the president’s help. Plus, Houston and its suburbs are exactly the sort of place where Trump could hurt local congressional candidates more than he helps.

Early last week, the Trump campaign announced that the president would hold a rally Monday at the NRG Arena in Houston, which can hold up to 8,000 — and is far from the largest venue in the state. At least 90 Texas venues claim to be larger, and the Dallas Morning News noted that the NRG Arena “isn’t close to the biggest event site even in Houston.”

The venue choice prompted online mocking — especially because Cruz’s opponent, Rep. Beto O’Rourke (D-Tex.), recently held an outdoor concert with musician Willie Nelson that attracted more than 50,000 people.

On Thursday, however, Brad Parscale, Trump’s 2020 campaign manager, announced that because of “HUGE and unprecedented” demand the event had been moved to the Toyota Center in Houston, which can hold up to 19,000 people. Although the arena is much larger than the original choice, it still isn’t one of the state’s top 20 biggest venues — there’s even a high school football stadium that can hold slightly more people.

A campaign spokesman said Saturday that officials first booked the smaller venue because “we were under a deadline to secure a contract” but that they had “continued to push for and negotiate terms for the larger capacity.” The campaign declined to answer other questions.

At Trump’s rally Oct. 13 at Eastern Kentucky University in Richmond, a few thousand people were turned away at the door, often after waiting for hours. Most of those who did not get inside left — after all, the temperature was about 47 degrees. A few hundred protesters gathered nearby but also left after Trump’s motorcade passed.

“We were so close!” a father said to his young son when they learned the doors had closed. “We tried,” a woman said to those around her.

“I really would love to have seen him,” said Marilyn Staton, 70, a real estate agent who lives in the area and waited in line for more than three hours with her husband, Clinton, who teaches concealed-carry permit courses.

The Statons wore matching red sweatshirts with glittery gold letters they had ironed on themselves. Hers read: “God bless Trump.” And his said: “God be with Trump.”

“He knows that he has a big following here,” Staton said. “There are a lot of people here who are tired of what’s happened with the way the Democrats have been running our country . . . He’s for the people, for everybody.”

During the rally, Trump said he made the trip because he wanted to support Barr, who faces Democrat Amy McGrath, a former Marine fighter pilot and fundraising powerhouse.

“I’ve seen the crowds. You know, outside you have 25,000, 35,000 — some crazy number of people — and we set up movie screens,” Trump said. “We set up beautiful movie screens.”

The hundreds watching on a single screen outside burst out laughing at the president’s exaggerated number, which most figured was a joke.

“And to those people outside: We love you. We love you,” Trump said, to cheers inside and out. “You have to see the lines, they go all the way back, many miles. But a lot of them stayed, and they’re watching screens outside.”