If you've been following the Democratic primary, one thing might seem obvious: Bernie Sanders is woefully behind Hillary Clinton on foreign policy. He's stumbling, awkward, and gaffe-prone when he discusses or debates global issues. Sanders's campaign can't even name a single expert who's serving as a formal foreign policy adviser.

And when you talk to Democratic foreign policy hands, that's generally how many see it as well: that Sanders simply isn't a foreign policy candidate.

But that's not the whole story. It turns out there's a real contingent of scholars and think-tankers who think Sanders has a credible vision on foreign policy — one that's worth taking seriously.

"There's a whole bunch of people," Lawrence Korb, a senior fellow at the Center for American Progress, told me.

When Sanders first cited him as a foreign policy influence this January, he said, quite a few of those people contacted Korb to ask if he knew how they could link up with Sanders's campaign.

"After he mentioned me on CNN and Meet the Press, I was deluged with a lot of people with whom I had worked on the Obama campaign," he said. "Really good foreign policy experts."

Korb is careful to say that he doesn't support Sanders outright, but he does find him credible. And in his telling, and the telling of other experts I spoke to, Sanders is not as hopeless on foreign policy as he might seem, and represents an important corrective to stale Washington conventional wisdom.

The arguments for Bernie Sanders as a serious foreign policy candidate are not going to convince everyone — indeed, I can't say I came away fully persuaded. But those arguments are nonetheless worth considering, and may be more compelling at points than you might expect.

Does Bernie have a foreign policy?

The most common knock on Sanders is that he has virtually nothing to offer as a foreign policy candidate; that his constant references to his Iraq War vote mask a lack of any real views about today's challenges.

"A vote in 2002 is not a plan to defeat ISIS," as Clinton pithily put it in an early February debate.

But for some, Sanders's opposition to the Iraq War isn't a stale talking point, but rather a stand-in for a well-informed worldview.

"These are people who look at the Iraq War as the defining event of the 21st century, " Daniel Nexon, a professor of international relations at Georgetown University who's supporting Sanders, says.

For Nexon, politicians' positions on Iraq — both what they said before it and how they adjusted to the aftermath — speaks to the way they see America's role in the world as well as the use and limits of American military power.

If you look at Sanders's 2002 statement on the Iraq War, it's in some ways quite prescient. "Who will govern Iraq when Saddam Hussein is removed and what role will the US play in an ensuing a civil war that could develop in that country?" Sanders asked. "Will moderate governments in the region who have large Islamic fundamentalist populations be overthrown and replaced by extremists?"

By contrast, Sanders supporters look at the Libya intervention and ongoing calls for deeper involvement in the Syrian civil war — both of which Clinton has supported — and see a Washington that even today has failed to learn the lessons of Iraq.

"There are a lot of us who look back at the lessons of the past 16 years, and worry that the foreign policy conventional wisdom, which is being represented by some parts of the Clinton campaign … hasn't really learned these lessons," Nexon tells me.

The people I spoke to said Sanders's opposition to Iraq needs to be considered alongside his record in Congress on the use of American military force. "He voted for the Balkans, he voted for Afghanistan, and didn't vote for Iraq," Korb pointed out.

"Multilateral if I can, unilateral if I must," Korb says, summing up Sanders's vision for the use of American force abroad. "Military should be the last option, and … make sure you know what your objective is and that you're willing to use all necessary force. And if you can't answer those questions, don't do it."

Nexon pointed to a November speech at Georgetown University as the best example of Sanders's foreign policy thinking. There, he defined his own worldview against 70 years of American meddling abroad.

"Our response must begin with an understanding of past mistakes and missteps in our previous approaches to foreign policy," Sander said. "It begins with the reflection that the failed policy decisions of the past — rushing to war, regime change in Iraq, or toppling Mossadegh in Iran in 1953, or Guatemalan President Árbenz in 1954, Brazilian President Goulart in 1964, Chilean President Allende in 1973."

Sanders, they said, would also likely continue Obama's policy of reaching out to American adversaries. He supports the Iran deal, for example, and even endorsed moving toward full diplomatic relations with Iran at a January debate.

"I think what we have got to do is move as aggressively as we can to normalize relations with Iran, understanding that Iran’s behavior in so many ways is something that we disagree with," he said.

"They criticized him for talking about maybe having normal relations with Iran, [but] I think we ought to be moving in that direction," Korb says. "Nixon went to China! They were still helping kill Americans in Vietnam. … Roosevelt recognized the Soviet Union after he came in."

More generally, Korb and other Sanders-friendly experts see his foreign policy as a continuation of Obama's — pushed, if anything, in a more dovish direction.

"For too long, a restrained foreign policy has been associated with weakness," Nexon says. "What Sanders offers is not a huge set of position papers, but rather a set of dispositions and judgments that I think … would serve the country a lot better than what we've been getting."

There is a degree to which this articulation of Sanders's foreign policy does rely, as his critics point out, an awful lot on what Sanders opposes rather than on any affirmative policies or ideas he supports. The degree to which that constitutes a foreign policy likely depends on how important you think it is to overturn the bad practices as Sanders sees them.

Does Bernie know anything about foreign policy?

Okay, a reasonable skeptic might say, Sanders has a general sense of how he sees America's place in the world. But is he knowledgeable enough to handle, say, negotiations with China over the South China Sea? Up enough on Russia to understand whether to deploy troops to America's Baltic allies?

Sanders supporters readily concede that he doesn't have a full set of policies ready to go. But they argue that this is not the best metric for judging his suitability.

"This Washington game going on here — how many position papers can you produce that probably no one is ever going to read and will be overtaken by events — [isn't] very helpful," Nexon says.

Some point to Sanders's frequent references to older moments in US foreign policy history as a sign of expertise. While the senator's preoccupation with events from before the fall of the Berlin Wall has drawn some mockery, the people I spoke to saw it as evidence of more meaningful views.

"That's why I found his discussion of Iran in the last debate so important," Sean Kay, a professor of policy and government at Ohio Wesleyan University, says.

Sanders had raised the 1953 US-backed coup against Iranian Prime Minister Mohammad Mossadegh, which he cited as contributing to America's problems in the Middle East.

"The result of that, you had the Iranian Revolution coming in, and that is where we are today," Sanders had said.

"Iranians know that history. They live that history," Kay says. "It's very much part of the identity of the country today."

"When I deal with the Iranians, and I had dinner with [Foreign Minister Javad] Zarif after 9/11, they always bring that up," Korb says. "We always forget it."

In their view, then, Sanders's focus on history reflects a deeper understanding of the forces animating present-day foreign policy challenges.

Still, the primary criticism of Sanders's foreign policy remains: He has not shown how understanding this history leads him to superior policies, or any policies at all, on present-day challenges. And his knowledge of those challenges still looks substantially thinner than Clinton's — or that of, say, Marco Rubio.

Sanders backers, when you raise this with them, say we should be careful not to put too much emphasis on the seeming expertise of his opponents.

"We shouldn't confuse a facility with repeating back talking points with foreign policy expertise," Nexon says. "You can have all the knowledge in the world and still advocate the wrong policies."

Why does Bernie Sanders seem so awkward when talking about foreign policy?

The people I spoke to argued that Sanders's seeming awkwardness with foreign policy reflects, to some degree, politics that are unrelated to actual facility or expertise.

At first, Sanders's campaign was designed more as a protest candidacy than anything else, created to highlight income inequality and money in politics. So there was no need to prepare a complete slate of policies.

"When they set up their campaign, they didn't think [foreign policy] would be an issue," Korb said. "They thought that they both [Clinton and Sanders] agreed on it; he was focused on the domestic."

But once Sanders's message began succeeding, he had no reason to shift away from his core domestic issues to foreign policy.

"It hasn't been, up until recently, a significant priority [for Sanders]," Kay says. "As I look at primaries over time, it's pretty rare where foreign policy is a major emphasis."

It's telling, on this point, that Clinton hasn't devoted a lot of time to foreign policy either. Though she has raised it at points, her attacks on Sanders focus more on his record on guns and social policy, issues nearer to the concerns of the Democratic electorate.

The media may play a role here as well. Sanders, lacking Clinton's public record on foreign policy, comes under much more scrutiny to prove his credentials. His mistakes get graded more harshly, his errors amplified.

That being said, Sanders supporters can't wish away the foreign policy gap. It's real.

My conversations with these foreign policy experts convinced me that there is at least a potential case to be made for Sanders on foreign policy. But ultimately he is the one who has to make it.

For Sanders, making that case will require proving that his judgment on Iraq in 2002 and his knowledge of foreign policy history can indeed lead him to actual answers on present-day challenges. Maybe he can in fact do that. But he hasn't yet.