"I am pleased to announce that Bill Stepien has been promoted to the role of Trump Campaign Manager," the president wrote on Facebook, amid a Twitter outage due to several high-profile accounts being hacked.
Parscale, who served on the 2016 campaign as the digital director, and who sources say has been breathlessly loyal to the president but politically over his head, will stay on to lead digital and data strategies, the president said.
The president offered the campaign manager role to Stepien during a private meeting Tuesday at the White House. Stepien was elevated to deputy campaign manager in late May.
The news comes nearly a month after what many close to the president viewed as a catastrophic error in Tulsa -- promising Trump a rally with thousands of packed supporters both inside and outside the BOK Center and only delivering a one-third full arena sparking days of national media coverage. And just last week, the president's reelection team again failed to reboot its campaign, canceling a rally in Portsmouth, New Hampshire, at the last minute, citing weather concerns publicly while privately campaign officials were fearful of a repeat of Tulsa, sources told ABC News.
Some close to Trump said the campaign shake-up will have little impact on the current state of the race given the president's refusal to change course.
"The president is still going to trample on the messaging being put out and spent millions on, moving Brad out doesn't change that," a Trump aide told ABC News.
Beyond the rally, public polling continues to show the president in dire straits, trailing presumptive Democratic nominee Joe Biden by double digits nationally and in many swing states.
In a Quinnipiac poll released Wednesday, Joe Biden had a 15-point advantage over Trump among registered voters. The poll also showed the president's approval rating sinking to dismal levels, with just 36% of registered voters saying they approve of the job he's doing as president while 60% say they disapprove. Among Republicans, 13% disapprove; among independents, 63% disapprove.
In the days following the Tulsa rally, Parscale face criticism over the move, even from within his own campaign, as 2016 campaign manager Corey Lewandowski, who also advises the 2020 campaign, called it a "fundamental mistake" in a radio interview.
"I lived this, as you know, I did this when candidate Trump was running. We won 38 primaries and caucuses under my stewardship, obviously all due to Donald Trump, but we never did something like this," Lewandowski said.
After the 2016 campaign ended and before being named campaign manager, Parscale joined America First, the super PAC endorsed by the president that works to support his agenda outside the White House, as a senior adviser.
The Texas-based digital guru has also done work on behalf of the Republican National Committee.
"Brad makes no secret of his past business success," campaign spokesman Tim Murtaugh told ABC News last August. "Since 2016 he has sold three start-up companies: Parscale Media, Giles-Parscale and a medical device company. He sold all these to focus full time on the president's reelection."
The Biden campaign responded to the change in leadership in the Trump campaign in a new statement from campaign spokesperson Andrew Bates, arguing that the campaign leadership wasn’t the problem.
"Almost 140,000 Americans have lost their lives and millions more have lost their jobs because of Donald Trump’s failed leadership," Bates said. "The Trump campaign’s game of musical chairs won’t fix this. We need a new president for that."
ABC News' Molly Nagle contributed to this report.