For now, the organized left is optimistic. In theory, OFA can bring immense resources to bear on issues like immigration and gun control, putting wind in the sails of the smaller progressive groups already fighting for reform. But there’s another side to that coin, progressive activists worry — should Obama support a budget package that includes, say, cuts to entitlements, the left may find itself battling OFA as it pushes Obama’s agenda. …

There are other potential legacies for OFA leaving a bad taste in progressive mouths. One liberal operative based outside the beltway complained that by taking unlimited donations — albeit with self-imposed corporate donation restrictions and donor disclosure rules — OFA was making it open season for politicians of all stripes to set up massive dark money machines to support their agendas.

“They’re setting a precedent that the GOP will follow. There’s nothing to stop [Speaker] Boehner from starting a C-4,” the operative said. “It’s the next step in an arms race and the potential for corruption is really problematic.”

Other progressives have worried that Obama’s speech to a group of high-dollar OFA donors signals that the group will offer access to the president for money. …