Anita Dunn, Biden's brawler-in-chief, looks to 2024

Anita Dunn saw an opportunity with "Dark Brandon."

The liberal meme, created by Joe Biden's most online fans as a play on the right-wing "Let's Go Brandon" code bashing the president, depicts a grinning Biden with red lasers shooting out of his eyes. After Dunn, Biden's top messaging and communications adviser, became aware of the meme, she brought it to the president - and they jumped on an opportunity to go on the offensive in the never-ending social media meme wars.

He's nodded to Dark Brandon in official speeches, aides have shared the image on social media, and his 2024 campaign is selling $32 T-shirts emblazoned with his online alter-ego. While it's a minor part of his repertoire, it shows how Dunn - a longtime Democratic operative and Biden confidante - has used her influence to engage in the kind of street brawling needed to combat perceptions of the aging president and the challenge ahead as he seeks a second term.

"It fits well with who she is, which is a f**k-sh*t-up-brawler. It's not a coincidence that the stuff that came behind Dark Brandon was very much in line with Anita's way of seeing the world," Rob Flaherty, the White House's director of digital strategy, told CNN.

CNN spoke to more than a dozen current and former White House and administration officials, lawmakers and Democratic strategists - many of whom requested anonymity to speak freely - who paint a picture of Dunn as a deeply loyal aide with a big-picture view of Biden's strategy - with a hand in nearly all aspects of his political life.

Her instincts for brawling are now directly intertwined with the president's political fortunes, as she bolsters an already expansive role as a presidential adviser with steering 2024 messaging from the White House. For a president who relies on a very tight circle of trusted advisers, sources say Dunn has emerged as a powerful chief political communicator, a key strategist and someone who will fight on his behalf. She takes these responsibilities on with a combination of deep experience and Biden's trust.

While sources both inside and outside the White House say no communicator is better prepared for the moment than Dunn, her messaging task ahead is massive: A high-profile candidate of Biden's age has never run before, and the president is facing low approval ratings after two years in the White House, which could be a drag on his reelection campaign. With Biden widely expected to face a familiar, but powerful, foe in former President Donald Trump, the mission facing Biden's advisers is to find a message that can resonate enough with voters to beat Trump again.