Priorities USA, one of the biggest liberal super PACs, will not run a single television advertisement in the 2024 election cycle.

Instead, the group announced Tuesday, Priorities USA is reshaping itself as a digital political strategy operation, the culmination of a yearslong transition from its supporting role in presidential campaigns to a full-service communications, research and training behemoth for Democrats up and down the ballot.

The move reflects a broad shift in media consumption over the past decade, away from traditional broadcast outlets and toward a fragmented online world. It also shows the growing role played by big-money groups in shaping campaigns and American political life: Priorities USA says it will spend $75 million on digital “communications, research and infrastructure” in the next year.

“We have learned that the internet is evolving too quickly for the traditional campaign apparatus to keep up in two-year cycles,” Danielle Butterfield, the group’s executive director, said in an interview. “We have committed to not just closing the gaps, but building infrastructure. We are not just focused on single-candidate investments.”

She added, “We are, I think, teaching folks how to fish.”

Ms. Butterfield said that more than half of that $75 million would be direct investments supporting President Biden’s re-election efforts and the campaigns of other Democrats on the ballot. Those plans, she said, will also have “embedded experiments” that will provide feedback on how people are responding to their efforts.

The organization said it was developing relationships with influencers and other “content creators” to spread campaign messages on platforms like TikTok. The group has also been working on “contextual targeting,” which it defined as presenting ads to voters based on what they were watching on their devices at any given moment.

Priorities USA also has a nonprofit arm that focuses on litigation and voter protection work.

Because of its size, the organization is essentially without peer or competitor in its new role, but Ms. Butterfield likened its new focus to that of the Center for Campaign Innovation, a conservative nonprofit group — not a super PAC — that is focused on digital politics.

Eric Wilson, the founder of the Center for Campaign Innovation, said Priorities USA’s change of focus “clearly shows that the way campaigns are going is around content creation and digital platforms.” While television advertising remains the best way to get a message in front of the most people, he said, “we are seeing diminishing returns on TV advertising — it’s becoming more expensive and less effective.”

“Media fragmentation is a big challenge for campaigns,” Mr. Wilson said, noting that the Center for Campaign Innovation does not work with campaigns. “You’ve got platforms that are banning political advertising. How do we teach campaigns to create their own content? What are the ways you can get political ads distributed, in a world that’s set up to block political messages?”

He added, “We spend a lot of time and investment figuring out how voters get information and why they make decisions.” (The Center for Campaign Innovation does not work with any campaigns.)

Priorities USA was formed in 2011 and supported Barack Obama’s 2012 re-election campaign, Hillary Clinton’s 2016 campaign and Mr. Biden’s 2020 campaign. It has relied on support from major Democratic donors; in 2020, former Mayor Michael R. Bloomberg of New York gave more than $19.2 million, campaign finance records show.

The group has expanded in recent years and has run digital training programs and an ad tracking service for strategists. It has also reached beyond presidential campaigns to work on Senate campaigns and state elections, including the recent Pennsylvania Supreme Court race.