A new $120 million pledge to lift President Biden and his allies will push the total expected spending from outside groups working to re-elect Mr. Biden to $1 billion this year.
The League of Conservation Voters, a leading climate organization that is among the biggest spenders on progressive causes, announced its plans for backing Mr. Biden on Tuesday, at a moment when his Republican challenger, former President Donald J. Trump, is struggling to raise funds. Mr. Biden’s campaign, independent of the outside groups, expects to raise and spend $2 billion as part of his re-election bid.
Republican groups are likely to spend big ahead of November, as well, but it is difficult to make direct comparisons between the Democratic organizations and their Republican counterparts. Democratic and progressive organizations often announce their spending plans before they have raised the funds, which often come in from small donors. Republican groups that rely more on major donors tend not to telegraph their plans.
The pro-Biden outside money originates from nearly a dozen organizations that include climate groups, labor unions and traditional super PACs. There are left-wing groups like MoveOn and moderate Republicans like Republican Voters Against Trump.
The largest spenders so far are Future Forward, the super PAC blessed by the Biden campaign, which has reserved more than $250 million in television advertising; the Service Employees International Union, which said last week that it would spend $200 million to back Mr. Biden and fellow Democrats; and American Bridge, the Democratic research organization that said in January that it planned to spend $140 million on an anti-Trump advertising campaign in battleground states.
“The sheer scale of what we’re talking about has never been seen before in our country’s history,” said Tiffany Muller, the president of End Citizens United, the government reform advocacy group working to limit the ability of these types of outside groups to spend unlimited sums on elections.
On Wednesday, the League of Conservation Voters is scheduled to host its annual dinner in Washington. Those expected to attend include Vice President Kamala Harris, Representative Hakeem Jeffries, the New York Democrat who is the House minority leader, and a handful of other Democratic members of Congress.
Pete Maysmith, the league’s senior vice president for campaigns, said the group’s funding would subsidize both an advertising campaign on television and digital platforms and also a field program that will encourage its members and supporters to tell their friends to vote for Mr. Biden.
“It’s hard to imagine higher stakes in these elections,” Mr. Maysmith said. “We will be communicating with voters in the battleground states and in the key races about the stakes, why President Biden has been such a champ on climate change and the obvious and extreme peril of having Donald Trump and his MAGA acolytes and big oil pleasers back in office for another four years.”
Stephanie Schriock, the former president of Emily’s List, the group that supports and funds Democratic women running for office, said she expected the amount of outside money backing Mr. Biden to reach $2.5 billion to $3 billion, with large sums to be spent on legal issues and get-out-the-vote efforts this fall.
Major Democratic donors, Ms. Schriock said, have been animated in recent weeks as Mr. Trump neared and then clinched the Republican presidential nomination.
“Folks just did not want to believe that it was going to be Donald Trump again,” she said. “The whole concept that this was happening again just sort of froze them and since Super Tuesday that has changed. People are like, ‘Oh, this is happening and this is real.’”
The $1 billion in Democratic money pledged on Mr. Biden’s behalf does not include an additional $239 million in advertising reservations made by Senate Majority PAC, the super PAC devoted to electing Senate Democrats. The super PAC that backs House Democrats, House Majority PAC, has not yet made its advertising reservations. A spokesman on Monday declined to reveal the group’s plans.
Nor does the $1 billion account for an expected influx in the tens of millions — if not more — from organizations that support Democrats including Planned Parenthood, and the political groups backed by Michael R. Bloomberg, the billionaire former New York mayor. Neither Planned Parenthood nor Mr. Bloomberg’s groups have announced their spending plans for the 2024 election, but past outlays have been significant.
One Republican group that has made public its plans is Faith & Freedom, the conservative organization led by Ralph Reed, a Trump ally, which said last week that it would spend $62 million to register and turn out evangelical voters for Mr. Trump.
Senate Leadership Fund, the super PAC that backs Senate Republican candidates, has also reserved $130 million in advertising time for the Senate races in Ohio and Montana.
The main Trump super PAC has spent $380,000 on radio ads targeting Black voters. On the day of Mr. Biden’s State of the Union address this month, another pro-Trump super PAC spent $500,000 on TV ads.
The disparity between the pro-Biden and pro-Trump outside groups echoes the cash advantage Mr. Biden’s campaign has over Mr. Trump’s.
Mr. Biden’s campaign announced on Sunday that it, along with the Democratic National Committee and affiliated fund-raising organizations, entered March with $155 million in cash on hand. The Trump campaign and the Republican National Committee had around $40 million at the end of January. The groups have not released a more recent total.
The Biden campaign is forbidden from coordinating with the outside groups but has encouraged their help publicly.
“These are real and meaningful investments that we expect will go to reaching the voters who will decide this election, while Donald Trump and a cash-strapped Republican Party continue to show zero interest or ability to build a winning coalition,” said Julie Chávez Rodríguez, Mr. Biden’s campaign manager.
Mr. Maysmith, at the League of Conservation Voters, said his group would work in tandem with other pro-Biden super PACs to avoid duplication and amplify their efforts. He said there were already plans underway to speak to voters who are inclined to back Mr. Biden’s climate agenda but who have concerns about his age.
“If they are raising a concern about the president’s age, we are absolutely ready to hear that, acknowledge that and then articulate why the president might not be the youngest guy out there, but he has delivered more on climate change than any other president in the history of this country,” Mr. Maysmith said.
Other groups backing Mr. Biden that have announced their 2024 spending plans include VoteVets, the Campaign for a Family Friendly Economy, the pro-Biden super PAC Unite the Country, and Climate Power, which announced an $80 million plan last year.
Ms. Muller said the enormous expenditures by outside groups could, if Mr. Biden is re-elected with Democratic majorities in Congress, lead to long-sought limits on the flow of such large sums into the American political ecosystem.
“It is possible for the voters’ trust to continue to be eroded,” she said. “There’s not too much room left for it to fall.”
