The news was greeted with a major sigh of relief in Democratic circles: philanthropist George Soros had decided to open his checkbook — to the tune of $2 million — to several liberal outside groups, the leading edge of what is expected to be $100 million in spending by the Democracy Alliance, a group of major Democratic donors.

George Soros, founder of Soros Fund Management LLC, speaks at Columbia University's sovereign wealth conference in New York, U.S., on Tuesday, Oct. 5, 2010. (Photographer: Stephen Yang/Bloomberg)

“As he has in the past, George is focusing his political giving in 2012 on grassroots organizing and holding conservatives accountable for the flawed policies they promote,” wrote Soros political adviser Michael Vachon in an email to donors on Monday night. “Both groups are part of a progressive infrastructure, or center left establishment, that plays an increasingly important role in elections.”

But, it may be where Soros and the Democracy Alliance are not giving money — at least not yet — that is the more important development, according to a number of Democratic strategists who pay close attention to the world of major donors.

If Soros and the Democracy Alliance decide not to use their deep pockets to fund Priorities USA Action, a super PAC formed by two former White House officials with the express purpose of running television ads in the presidential race this fall, it could make it difficult for Democrats to stay competitive on the TV airwaves.

At the end of March, Priorities USA Action had $5 million in the bank while American Crossroads, the major player in conservative outside money circles, had $24 million on hand. (Crossroads has pledged to spend upwards of $200 million on the presidential race — largely through television ads.)

That disparity coupled with Soros and the Democracy Alliance decision to fund things other than TV ads has some within the party worried.

Bill Burton, who runs Priorities USA Action, warned that “there is an ocean of half a billion dollars about to wash over President Obama and the things progressives really care about,” from conservative groups. “We are buuilding an organization to combat that. We got a job to do and we are going to do it.”

Added one senior party operative who closely monitors outside group spending. “If Democrats cannot be competitive with paid media, seats will be lost and the presidential race will be severely imbalanced, making it far harder to build anything longer term.”

Another senior party strategist took it even further, arguing that Soros’ decision to pass over Priorities is evidence of the ongoing riff between liberal donors and the Obama White House.

“Obama continues to be a disappointment to them,” said the source. “While they will vote for him given the alternative, they won’t be doing it with their pocketbook.  The groups they are supporting are part of the progressive infrastructure as opposed to candidate Obama.”

Vachon cast Soros’ donations as consistent with more than three decades of giving — in the U.S and abroad — to organizations that support the broad construction of democratic organizations. He added that Soros “has never liked the idea of spending money on political has never appealed to him. He doesn’t like politics by ads.”

Vachon added that while Soros is focused on organizations that build longer term infrastructures, it is not a broader commentary on Priorities USA or other super PACs. “Donors who are so inclined should support the super PACs, absolutely,” he said. “The conventional wisdom that Democrats can’t unilaterally disarm is correct. Advertising just isn’t what George has historically done.”

One source involved in the world of major Democratic donors cast the decision by Soros and other major liberal givers to fund grassroots and research operations rather than a massive television campaign as a bit of realpolitik.

“The investments reflect an understanding that progressives won’t match the flood of conservative money on the airwaves and need to play to our strength on the ground,” said the source.

All of the above could well be moot if Soros and other well-heeled Democrats eventually decide to pump money into Priorities USA Action. (Soros as well as the other members of the Democracy Alliance have more than enough cash to fund both the grassroots efforts and the paid media efforts of the party if they so choose.) And, there are plenty of affluent liberal donors who aren’t members of the Democracy Alliance who could well fund Priorities on their own.

But, if a major segment of Democratic givers have decided that their money is best spent on continuing to build a broad grassroots infrastructure rather than match conservatives ad for ad in the coming months, it will, almost without question, impact the fight for the presidency this fall.