Earlier this year, every Republican from President Donald Trump on down said they wanted to repeal Obamacare. They just couldn’t agree on what to replace it with — a disagreement that, as we know now, made it impossible to get rid of the law. It turns out just promising to do “the opposite of what President Obama did” isn’t enough.

There’s a growing worry on the left that Democrats are plagued by a similar kind of problem — but on foreign policy rather than health care.

On issue after issue, from the war in Afghanistan to the rise of China, Democrats have little exciting to offer. Democratic members of Congress are happy to give fiery speeches condemning Trump’s policies on terrorism or Russia, but that’s not very different from what Republicans did on health care while President Barack Obama was in office.

This isn’t because Democrats don’t have any policy ideas in general. In fact, the party is teeming with them: Various Democrats in Congress, including some 2020 presidential prospects, have advanced new ideas on issues ranging from tweaking Obamacare by allowing all Americans to buy-in to Medicaid, to addressing structural racism in the criminal justice system by paying states to reduce their prison populations, to stopping the rise of monopolies in the tech field by requiring the Federal Trade Commission and Federal Communications Commission to protect small tech companies from anti-competitive practices. On many of these issues, the party has moved substantially to the left of where it has been in the past.

But on international affairs, Democrats have far fewer exciting ideas to offer.

When Trump announced his decision to keep fighting in Afghanistan in late August, for example, the party had no unified alternative plan for the country. Leading 2020 hopefuls like Sens. Cory Booker and Kamala Harris didn’t even issue a statement on America’s longest-running war. The most recent Democratic Party standard bearer, Hillary Clinton, sounded very similar to Republicans on foreign policy. On Syria, for example, her plan — imposing a no fly zone over a swath of the country and increasing US support for rebels fighting Syrian President Bashar al-Assad — is strikingly similar to ideas you hear today from congressional Republicans like Sens. John McCain and Lindsey Graham.

So what’s going on? Why are Democrats so bereft on foreign policy?

To find out, I talked to a half-dozen people with experience in the liberal foreign policy world, ranging from congressional staffers to professors to former White House officials. Most of them pointed the finger at something that might not seem obvious: Think tanks.

Think tanks are peculiar beasts. In their ideal form, they’re supposed to be like universities without students, where scholars sit and dream up ideas. What they mostly do is provide politicians with ready-made ideas they can seize upon as their own solutions to pressing national problems.

Congressional staffs and party officials often have their hands full just doing their day-to-day jobs, and true academic scholarship typically doesn’t focus on developing actionable policy ideas. Think tanks bridge the gap, translating academic knowledge into concrete proposals policymakers can use. They’re also a place to produce talent, to groom officials who can take new positions when there is a transfer of power.

The best progressive think tanks do excellent work on domestic issues. But in the national security space, most of what they produce is similar to policies produced by down-the-middle centrist operations. Progressive activists have spent years trying to figure out how to build up a more robust think tank architecture, but they keep failing — to the point where they’re not even sure how it could be done.

“This is literally a question I’ve sat up at night anguishing about for a decade,” says Heather Hurlburt, the final director of the National Security Network, a progressive foreign policy think tank that shuttered its doors in 2016.

A major part of the problem is the money: Rich liberal donors were interested in funding national security policy work after the 2003 Iraq invasion turned into a fiasco, but their interest has petered out in recent years. Another part of the problem appears to be liberalism itself: The liberal base is highly divided over the use of American military power and Washington’s place in the world.

No one seems to know how to overcome this. But there’s a clear consensus in liberal circles — even at the highest levels — that the lack of think tank firepower is a real problem.

“It is a real question as to what can be developed in terms of infrastructure in the next couple of years,” Ben Rhodes, deputy national security adviser under President Obama, tells me. “You don’t want to end up in a position where Trump may just kind of implode, and yet the national security debate is still essentially framed by the right.”

The progressive foreign policy architecture is really weak

Every year, the University of Pennsylvania ranks the top think tanks in the world according to their impact on policy and their ability to attract attention to their ideas. In the most recent edition (2016), four out of the top 10 were American institutions that focus exclusively on international affairs: the Center for Strategic and International Studies (CSIS), the Carnegie Endowment for International Peace, the Woodrow Wilson International Center for Scholars, and the Council on Foreign Relations (CFR).

These four institutions are scrupulously nonpartisan, devoted to developing policy ideas that centrist members of either party could pick up and use. Which means that, for the most part, they’re committed to US involvement in the world, supportive of US military intervention abroad, and in favor of free-trade agreements like NAFTA and other forms of globalization. You see a similar worldview at nonpartisan think tanks that do both foreign and domestic policy, like the Brookings Institution (the top-ranked think tank in the Penn list).

This isn’t a knock against these institutions: They do a lot of rigorous work and come up with valuable policy ideas. It’s just that they have a lot of assumptions in common and tend to recommend strikingly similar things as a result.

There’s another group of think tanks that are affiliated with a major political party or body of ideas. Four of these rank in the top 30 on the Penn list: the conservative Heritage Foundation and American Enterprise Institute (AEI), the libertarian Cato Institute, and the center-left Center for American Progress (CAP, where — full disclosure — I worked from 2012 to 2014).

Heritage and AEI are behemoths, spending $80 million and $47 million respectively in 2015 (the last year for which federal data is available). They have influential, well-staffed foreign policy programs — all of which advocate for a more aggressive, military-focused foreign policy. James Jay Carafano, the director of Heritage’s national security program, advised the Trump transition team and has personally briefed the president on foreign policy issues.

CAP is the only progressive group in that same weight class, spending slightly more than AEI did in 2015. It’s widely recognized as a powerful force in the Democratic Party, playing a vital role in shaping the original drafting of Obamacare (among other things). Yet the experts I spoke to were virtually unanimous in saying that neither CAP nor any other liberal think tank is as important on foreign policy as the conservative ones are.

“At Heritage and AEI on the right, there’s just a more robust effort to frame the debate, particularly around issues having to do with the use of military force and counterterrorism, than any comparable effort on the left,” Rhodes says. “I did feel like, on some of the tougher fights [the Obama White House faced], there was a lack of a broad spectrum of views.”

Part of the reason is that CAP invests more energy and resources on domestic policy. But it’s also because its policy preferences on foreign affairs aren’t all that different from those of the more centrist organizations. In 2009, for example, CAP counseled Obama to deploy 17,000 more troops to Afghanistan and keep them there for 10 years. You heard similar proposals from Republicans in Congress and Heritage scholars.

The result is that Washington’s foreign policy debate tends to be mostly conducted between the center and the right. The issue is typically how much force America should use rather than whether it should use it at all, or how to tweak a free-trade agreement rather than whether it should be accepted at all. Debates over pressing policy issues — from fighting ISIS to the crisis in Venezuela to handling Chinese provocations in the South China Sea — lack a left-wing voice of any prominence.

“What’s happened on the left is a complete atrophy of any kind of alternative thought,” says Dan Nexon, an international relations professor at Georgetown who advised Bernie Sanders’s presidential campaign on foreign policy.

Why the think tank gap matters

The consequences of this think tank gap are very real.

Think, for a second, about how ideas translate into laws and policies. The first stage is a basic idea — like, say, negotiating with Iran to end its nuclear program. The second stage is someone developing a detailed policy proposal for making that basic idea a reality, like a white paper explaining what the US should be prepared to offer Iran and what it should ask for in exchange. Third, elected officials and civil servants try to implement these ideas — in the Iran example, though a series of complex negotiations and eventually a written legal document (the Iran deal itself).

It’s that second stage — detailing how a vague idea could be translated into specific policies — where think tanks really matter. They do the time-consuming work of turning general positions (“we should withdraw from Afghanistan”) into actual policy ideas (“here’s exactly how and when we should pull troops out”) that elected officials and their overworked staffs often don’t have time to do.

The absence of this kind of detailed policy work on the left makes it difficult for left-leaning politicians, like Bernie Sanders and Elizabeth Warren, to translate their general left-of-center principles into actionable policies. Without ready-made policies to pull from, it’s harder for them to engage on foreign affairs in the same way they do on domestic issues.

That’s the concrete way that the lack of left-wing foreign policy think tank work pushes foreign policy to the right.

“This is the iron law of ideas: You can’t beat an idea unless you take the time to think of a better one,” says Dan Drezner, a professor at Tufts University’s Fletcher School and author of The Ideas Industry, a book on think tanks. “At least on foreign policy … there’s not a lot of nitty-gritty [on the left].”

This issue has been well known on the broader left since at least the runup to the Iraq War. In 2002, Hurlburt wrote a piece in the Washington Monthly bemoaning the poor state of the left-wing thought architecture, blaming the lack of alternative Iraq policies on the fact that “the Democrats [have] no institutional or organized way to think through national security issues.”

As the 2003 invasion devolved into a bloody civil war, it looked like that might change. Iraq became the core energizing issue on the left, leading to huge amounts of donor and activist interest in foreign affairs more broadly. CAP was founded in 2003 as an intentional counterpoint to the right-wing think tanks that backed the war. It put significant resources into developing a withdrawal plan, unveiled in 2005, that argued for a phased departure from Iraq beginning in January 2006 and ending in December 2007.

But the Bush administration had no interest in listening to its left-wing critics, and surged troops into Iraq. When Obama was elected in 2008, the left had a much better chance to influence foreign policy, the funding and activist energy suddenly started to dry up. It seemed that left-wing interest in world affairs had been driven principally by opposition to Bush’s Iraq policy. With Obama, who had promised to end the Iraq War, now in office, the perception of crisis was gone — and with it, the resources.

“You don’t have a lot of really innovative intellectual thought on policy when you’re in power,” says Nexon, the Georgetown scholar who advised the Sanders campaign. “Most people are in the administration, trying to influence policy.”

Conservative interest in foreign affairs, by contrast, remained sustained in the think tank world. Right-leaning foreign policy shops that started during the Bush years, like the Foundation for the Defense of Democracies and the Institute for the Study of War, grew even more influential during the Obama administration — playing a major role on the Iran deal and the debate over fighting ISIS (respectively).

The closest thing to a liberal equivalent of those groups is the Center for A New American Security (CNAS). It was founded in 2007 by two leading Democratic foreign policy experts, Michèle Flournoy and Kurt Campbell, who would both go on to serve in high-level roles in the Obama administration. It does do some exceptional policy work, particularly when it comes to terrorism and counterinsurgency.

But CNAS has always pushed away from its liberal identity. It styles itself a nonpartisan, nonideological shop, and (like CAP) generally offers policy recommendations quite similar to what you see from centrist think tanks.

“CNAS represents the old George H.W. Bush view on foreign policy; some people would say it’s the Hillary Clinton view — it’s just where the US government has been for a very long time,” says Mieke Eoyang, vice president for national security at the center-left Third Way think tank.

The result is that while the right has a distinctive and powerful foreign policy echo chamber, the left has no real equivalent. So when Trump won the 2016 election, Democrats were poorly equipped to oppose his foreign policy proposals. Obama’s policies basically became the progressive agenda on foreign policy for eight years; congressional Democrats mostly followed his lead. Now all of a sudden Democrats had to think for themselves, and they found themselves as bereft of distinct ideas as they were in 2002.

“One of the more depressing aspects of my adult life is how true that piece still is,” Hurlburt says of her 2002 essay on the left’s lack of foreign policy institutions.

The result is that the progressive pushback against Trump’s foreign policy has been quite weak.

“All there is is Trump ... a right-wing ecosystem, and a fairly hawkish and interventionist foreign policy establishment,” Rhodes says. “It would almost be difficult for someone to find the alternative views on Afghanistan or the Middle East.”

The problems: money and ideology

So if this gap is a problem, and left-wing policy experts are aware of it, why does it persist?

The first answer, experts say, is donors. Think tanks need money to pay researchers, administration staff, and office rent. They often get that money from large corporations and foreign governments, which aren’t typically great sources for someone looking to start up a progressive foreign policy shop. The most promising sources are rich left-leaning donors like billionaire businessman George Soros.

The problem, though, is that it’s been difficult to find any such donor who’s interested in a truly progressive foreign policy. There are plenty of liberal donors who want to fund domestic progressive causes — billionaire Tom Steyer funds a ton of climate change initiatives, for example.

There are also a number of donors, like Microsoft founder Bill Gates and media investor Haim Saban, who are willing to fund work on specific foreign issues (international development and the Middle East respectively) but not a broader progressive foreign policy think tank architecture.

“The reason [the right has foreign policy think tanks] is there are donors who really believe in that worldview,” Drezner says. “That doesn’t seem to be the case on the left.”

But this answer — that the donors just aren’t there — raises an important question: Why is it that liberal, progressive donors are generally uninterested in funding foreign policy think tanks? And why has this been true for decades, with the Iraq War being the exception that proves the rule?

The best answer, experts say, is that there’s something about liberalism itself that makes its adherents less interested, on the whole, in developing policies on foreign affairs.

Broadly speaking, modern American liberalism is oriented around the ideal of social equality. Activists and base voters are motivated to address racism, sexism, and economic inequality, leading to a lot of policy thinking focused on how to reduce police violence or expand access to health care.

The best left-wing foreign policy ideas — like restricting Bashar al-Assad’s ability to borrow money (instead of deploying the US military to Syria), limiting arms sales to authoritarian countries like Saudi Arabia, giving special trade privileges to oil-rich countries like Angola if they funnel oil profits to ordinary citizens rather than the wealthy, or getting the US to pledge never to use nuclear weapons first in a conflict — fit with this tradition. These policy ideas all aim to decrease the risk of mass violence while (in theory) helping the world’s most vulnerable people.

But the issues that those policies are trying to address just don’t seem to excite liberal passions about equality and fairness in the way that police shootings or shuttered abortion clinics do. It takes a high-profile national crisis, like the disastrous Iraq War, for the consequences of US foreign policy to feel as real as those other domestic issues.

“People get animated about policy when they look at an issue and think, ‘There’s a problem here,’” Drezner says. “For Democrats, inequality is a problem. Racial divisions are a problem. Wage stagnation is a real problem. These are serious issues that affect, in theory, the Democratic base — foreign policy doesn’t.”

The tools of foreign policy also sit uneasily with the liberal conscience. Diplomacy and foreign aid are fine, but economic sanctions and the use of military force will always be controversial among people on the left. Think about the fraught debates in 2011 over humanitarian intervention in Libya, for example — in which some liberals argued that the US had a duty to stop Muammar Qaddafi from killing while others warned of the consequences of another war for regime change.

“As progressives, we believe in government. And yet, the logic of a security state tends in directions that are antithetical to things we believe as progressives,” Hurlburt says. “As a security progressive, you’re constantly riding that contradiction, and you’ll never get away from it.”

This makes it harder for donors to know who, exactly, they should be listening to when it comes to foreign policy — or, more specifically, who they should be funding. This is further complicated by liberal fears of being labeled soft on defense and national security, which Drezner calls a “30-year issue” for the party.

But such problems are not insurmountable. After all, conservatives have their own divisions on foreign policy and the use of force, many of which have been highlighted by the Iraq War and the Trump administration. Yet they’ve managed to build up robust foreign policy institutions.

That was mostly because history left them in a strong place. The main push to build up conservative think tanks came during the Cold War, especially the Reagan years, when foreign policy (specifically, countering communism and the Soviet Union) was a big uniter for the conservative movement. That created a large cadre of donors and activists committed to a hawkish foreign policy, many of whom have continued influencing the foreign policy debate for decades.

Democrats hope that the Trump administration will be a similar unifying motivator.

“Trump offers an enormous opportunity to progressives, because he’s frankly left the field on issues — like core alliances, the promotion of democracy and American values around the world — that the Republican party embraced for decades,” Rhodes says. “What I believe the Democratic Party can do, that progressives can do, is essentially claim the mainstream space of the basic conduct of American foreign policy.”

But the issues in the Trump administration that have gotten the most attention on the left, things like the Muslim ban and his response to Charlottesville, don’t focus on foreign policy proper. Even the Russia scandal isn’t really about Russia policy. Which means there’s a real chance that, as happened during the Iraq War, progressives will fail to solve their foreign policy problem.

“I get people calling me and emailing me asking, ‘We need to get our act together, how do we do it?’” Nexon says. “And I say, ‘I dunno, you tell me.”’