“There’s a base of progressives out there nationally looking for a voice, and they’ve been funding people for a while,” says O’Malley senior adviser Bill Hyers, who managed liberal darling Bill de Blasio’s New York mayoral campaign in 2013. “There’s definitely a group we can tap into that is looking for Gov. O’Malley.”

But as O’Malley seeks to sharpen the contrast with Clinton, aides said, he is unlikely to lash out at her directly anytime soon.
Instead, he will continue to point out her policy shifts, talk about a need for new leadership and tweet videos highlighting his stances on specific issues when he and Clinton disagree, according to people familiar with his plans.

While the O’Malley brain trust is invested in raising the likely candidate’s name recognition levels in the early-voting states, his advisers see no benefit in doing so by attacking Clinton, whose campaign looks and feels like a juggernaut. It’s not productive for O’Malley to become known for anti-Clinton attacks, they believe, preferring that he focus on specific issues — like strengthening Wall Street regulation and opposing the Trans-Pacific Partnership trade deal — that excite liberals.

Ultimately, his strategists hope to position him as a liberal with executive experience, funded largely by a robust online donation operation.