Nicholas Confessore / New York Times News Service

Liberal and Democratic-leaning groups, facing difficult midterm elections next year without the technological muscle of the Obama campaign behind them, are preparing a major effort to improve their data infrastructure.

George Soros, the retired hedge fund billionaire and longtime patron of liberal causes, will invest $2.5 million in the effort, officials involved with the plan said. His participation is a signal that some of the wealthy donors who arrived late to the Democrats’ “super PAC” efforts in 2012 are committing early for the next round. The initiative opens a new front in the “big data” arms race between the left and the right, as the Republican Party and conservative outside groups pour money into political technology after a presidential campaign in which they were badly outmatched.

President Barack Obama’s campaign spent tens of millions of dollars building a program to identify likely supporters and to motivate them with ads, social media efforts and get-out-the-vote messages. But the data experts and engineers who built Obama’s tech programs have largely moved into the private sector. And the president’s political organization faces an uncertain future: Reborn after Election Day as a tax-exempt advocacy group, it has struggled to translate Obama’s millions of supporters into an effective tool for advancing his agenda on issues like guns and immigration.

More important, some Democrats said, is that they are unsure how big a role that Obama’s organization can — or will — play in 2014. Those involved with the new effort say they are not waiting to find out. The initiative, as yet unnamed, will be based at Catalist, a for-profit cooperative founded in 2006 by Harold Ickes, a former aide to Hillary Rodham Clinton, and others.

Details of the effort were presented this week at a Washington conference of the Democracy Alliance, a coalition of some of the country’s biggest liberal givers, which works to steer money and to coordinate political work among advocacy groups. Soros and other alliance donors were early investors in Catalist, and many of the groups funded by the alliance now buy data from it.

On Thursday, boldfaced names of the Democratic donor world mingled at the Mandarin Oriental Hotel with rising Democratic stars like Wendy Davis, a contender for the Texas governor’s race, and Sen. Elizabeth Warren of Massachusetts, who has been urged by some supporters to consider a presidential bid. Warren gave a speech touching on Republican efforts to filibuster Obama’s judicial nominees and the drive to bring intellectual diversity to the federal bench, attendees said, and she was warmly received.

“She’s been a darling here since the first time she came,” said Rob McKay, the alliance’s chairman.

The conference will also feature the installation of Gara LaMarche, a veteran of liberal philanthropy, as the alliance’s new president. In an interview, LaMarche said the alliance hoped to expand its donor base and double its giving over the next several years, in part for a major new effort to expand the liberal political infrastructure at the state level, where conservatives and Republicans have won a series of political and policy victories.

“There is a lot of feeling in this room that the states are where the focus should be,” LaMarche said.

Improving Catalist was part of that drive, alliance officials said. The group serves as a kind of data hub for dozens of labor unions, liberal advocacy groups and super PACs, maintaining a shared national voter file that is continually updated with commercial and consumer data. Catalist was also involved in the governor’s election this month in Virginia and in the victorious mayoral campaign of Bill de Blasio in New York City.