In a crowded Democratic presidential primary field, there is one candidate who has drawn sustained opposition from party elites: Vermont’s Senator Bernie Sanders. The New York Times reports that major donors, party operatives, senior lawmakers and rival candidate and South Bend Mayor Pete Buttigieg have been attending private meetings where they discuss, among other things, how to prevent a Sanders nomination.

One explanation for why a party would try to stop the ascendancy of a certain candidate is electability. But that explanation is weak: Sanders has maintained high national favorability ratings, and is outperforming the incumbent Republican, Donald Trump, in polling.

Another explanation would be that the dispute is interpersonal in nature. A dramatic New York Times anecdote noted that Sanders’s campaign manager, Faiz Shakir, was once punched or shoved, depending on whose story you believe, by the then Hillary Clinton aide Neera Tanden during a dispute in 2008. Tanden is a known longtime critic of Sanders and the president of the Center for American Progress (Cap), a liberal thinktank that came under fire from Sanders when its weblog ThinkProgress produced a video drawing attention to his wealth.

But is this just about residual bad blood between Clinton and Sanders factions?

I don’t think so. Between 2009 and 2012, I worked for both Shakir and Tanden at the Center for American Progress. Shakir was the editor-in-chief of ThinkProgress at the time and we both worked under Tanden.

Shakir and Tanden frequently clashed during my time there, but not a single one of their disputes was about anything personal. Instead, they argued about the role of money in politics.

Although Cap is a thinktank that produces policy papers – many of which are commendable – it is also serves as an important political unit allied to the Democratic party. It promotes its policy stances to Democratic party politicians and works to get its staff hired into Democratic administrations. But it does so in a climate where big donors – banks, healthcare firms and foreign governments make up its donor rolls – frequently pressured it to adopt certain stances.

As one example, stories I reported for the Intercept showed that the UAE paid Cap $2.5m as its senior staff helped them lobby the Trump administration and influence the wider DC policy community.

During my time at the thinktank, Shakir repeatedly and vigorously pushed back at attempts by Cap’s donors to influence ThinkProgress’s content, while Tanden argued that this was simply the cost of doing business in Washington. It is hardly any surprise that she boasted about recruiting a pro-Israel board member and donor, after her invitation to the Israeli prime minister, Benjamin Netanyahu, to address her thinktank. In Tanden’s mind, a thinktank like Cap can only maintain its influence through strong elite fundraising, so any cost in reputation it suffered by inviting Netanyahu was offset by the money.

The Shakir-Tanden debate about money in politics at Cap is also the larger debate Sanders is sparking in the Democratic party. Joe Biden opened his presidential bid by allowing a Comcast executive to host a fundraiser for him at his home in Pennsylvania. Sanders, on the other hand, has written off such fundraisers and is insisting on relying on small donor funders, not corporate executives or lobbyists.

It may sound like I am portraying Tanden, Biden and the Democratic establishment as corrupt and immoral – willing to sell policy and political communications to the highest bidder with no regard for the public interest.

But social psychology research tells us that people who have different ideas about politics than us are not generally bad people – they’re mostly good people with different convictions. In the eyes of the Democratic establishment, courting big dollars is the only way to stay politically competitive – and besides, corporations and wealthy individuals are major stakeholders in society, so why shouldn’t they get a major say over policy?

That’s a coherent worldview, and it’s one that the majority of Democratic and Republican powerbrokers hold. But increasingly, American voters are turning against what they see as a corrupting influence of money in our politics. Sanders believes that he can build a sort of politics where small donors and ordinary people drive political discussion rather than the large donors Cap and Biden are courting.

Establishment voices will probably mock Sanders’ view as naive or overly idealistic. But if you think about what Sanders is arguing, perhaps he is the realist.

In 10 years of reporting about politics, almost every politician has told me their donors do not influence their behavior. If this were true, they would be the only individuals on planet Earth who are not tempted by money.

What Sanders is arguing is the opposite – if he started doing big-ticket fundraisers with corporate executive and lobbyists, he would be influenced by their money. He is admitting his human flaws, and taking corrective action to make up for them.

If anything, the establishment’s argument is the idealistic one, and Sanders’ is the pragmatic one.