Though otherwise impressed by his bold positions on economic inequality, climate change, and getting money out of politics, progressive campaigners on Thursday presented presidential candidate Sen. Bernie Sanders with a demand that he take a much stronger position against U.S. militarism, endless war, and a bloated Pentagon budget that directly impedes the other social investments for which he so strongly advocates.

Organized by the online group RootsAction.org, a petition signed by more than 25,000 people—many of whom are actively supporting his campaign—was delivered to Sanders' campaign headquarters as a way to highlight the intersection of military spending and corporate power and to hold the candidate's feet to the fire on key issues of foreign policy.

The petition itself reads:

"Senator Sanders, we are enthusiastic about your presidential campaign’s strong challenge to corporate power and oligarchy. We urge you to speak out about how they are intertwined with militarism and ongoing war. Martin Luther King Jr. denounced what he called 'the madness of militarism,' and you should do the same. As you said in your speech to the SCLC, 'Now is not the time for thinking small.' Unwillingness to challenge the madness of militarism is thinking small."

Though huge crowds are still swarming to Sanders' populist campaign and a new poll released Tuesday showed him leading Hillary Clinton in the early primary state of New Hampshire, the longest-serving Independent in the U.S. Congress is still lagging far behind the former secretary of state and Democratic frontrunner in national polls.

Though the petition sent to Sanders on Thursday is clearly a challenge for the candidate to speak about specific issues he has tended to avoid, RootsAction co-founders Norman Solomon and Jeff Cohen made it clear that even as they support the campaign for its populist core, there remain critical gaps in his platform and stump speeches they believe ought to be addressed more frequently and forcefully.

"Bernie has been terrific in this campaign as he eloquently denounces corporate power, economic inequality and 'oligarchy,'" said Solomon. "But he’s not saying much about crucial issues of war, militarism and foreign policy—issues that have a great deal to do with a wide range of concerns that have been central to his grassroots campaign."

Solomon said his group launched its petition campaign because ongoing U.S. wars and huge military spending "continue to be deeply enmeshed with basic economic ills from upside-down priorities." Solomon cited data from the National Priorities Project which shows that 54 percent of the U.S. government’s current discretionary spending now goes to military purposes. "We sidestep these realities at our peril," he said.

RootsAction has said it will share any official response from the Sanders campaign with its online network, including those indivuduals who signed the petition.

Cohen says the Sanders campaign is barnstorming the country and garnering enormous support because he knows how to connect with voters by "arguing that a country as wealthy as ours should provide free college and healthcare for all and infrastructure jobs." But, he added, some of Sanders' most ardent supporters are still right to question how those much needed programs are "fundable unless billions of war dollars are redirected homeward."

Like most progressives, Cohen said he is thrilled that the Sanders campaign has aroused so much enthusiasm nationwide. Citing the endorsement that Sanders received earlier this week from the prominent academic and activist Cornel West—who grouped the populist candidate with other 'prophetic politicians' who deserve 'our critical support' despite 'their faults and blind spots'—Cohen said that sentiment is widely shared by progressives like himself and those who signed the petition.

"It is a serious 'blind spot' to denounce corporate power and oligarchy," Cohen concluded, "without emphasizing militarism and perpetual war."