Former President Barack Obama's chief strategist remains haunted by the thought that the entire Donald Trump era might have been avoided with a single phone call.

David Axelrod, who spearheaded both of Obama's successful presidential campaigns in 2008 and 2012 and later became a CNN senior political commentator, recounted to New York Magazine's Ben Terris a phone call he received in 2010 from Trump — then the star of "Celebrity Apprentice" and publicly teasing a presidential run — pitching a ballroom construction project at the White House. For decades, large White House events such as state dinners have typically been held in tents erected on the South Lawn because the building's interior entertaining spaces are limited.

"I build ballrooms," Trump reportedly told Axelrod. "I build the greatest ballrooms in the world — come down to Florida and see for yourself. You have these state dinners, and you have them in these s----- little tents in the back. It's not befitting. Let me build a modular ballroom for you. You can put it together, take it apart."

Axelrod considered the idea preposterous, he told Terris.

"We were just coming out of the worst recession since the Great Depression, and I'm pretty sure no one in America thinks our priority should be a ballroom for the White House," Axelrod said. The call came amid the sluggish recovery from the 2008 financial crisis, when the administration's political focus was on the economy and the newly passed Affordable Care Act.

Axelrod passed Trump's message along to the White House social secretary and assumed someone would follow up on the call — but that never happened.

"He was owed a call," Axelrod said. "I have no excuse for that."

Axelrod has occasionally wondered, though, how the last 15 years might have unfolded differently — from Trump's birther conspiracies to his ride down the golden escalator in June 2015 — had Obama's White House returned the call about the ballroom.

"If we had let him build his modular ballroom, perhaps we wouldn't have had to demolish the East Wing," Axelrod said. "And in that sense, I kind of regret not doing it."

The 80-year-old president told Terris he holds no grudge over the episode, but said it taught him something about the Obama administration.

"They're not good businesspeople," he said. "If somebody offers you a free ballroom, take it, right?"

Trump never let go of the idea of building a ballroom, and he even campaigned on the proposal at an Iowa rally in January 2016, telling supporters what he would bring to Washington.

"We'll get the top people, top everything — we'll have the best ballroom," Trump said in Sioux City. "Because I notice they always put tents up on the lawn. No. 1, it's not a good security thing. No. 2, the guy that owns the tents is making a fortune."

He told Terris he wanted to build a ballroom during his first term, saying he was embarrassed to invite foreign leaders to the White House without one, but the timing never felt right.

"In the first term, I was under siege," he told Terris. "I didn't feel it was the atmosphere ... [This] is a much more powerful time." The comment points to a potential revived push in his current term, though no such project has been announced.