When I sat down with Sen. Bernie Sanders (I-Vt.) last week, he was a bit annoyed — admittedly not unusual. He was just back from a news conference where he and Sen. Elizabeth Warren (D-Mass.) — among others — introduced the new Expand Social Security Caucus in Congress.

It barely made a media blip.

“Go out and ask people about the desperation many seniors are living under,” Sanders told me, picking up a copy of the most recent National Journal. The cover story? Meet 2020’s Millennial Kingmaker. “Isn’t that an issue everybody’s worried about?” he asked sarcastically.

It is not hard to understand why Sanders sounds so frustrated. Even as the once-radical Medicare-for-all and a $15-an-hour minimum wage turned into must-have policy accoutrements for Democratic presidential hopefuls, Sanders still feels his proposals are met with a fierce resistance from those who should like them.

Case in point: His recent Stop Bad Employers by Zeroing Out Subsidies Act, also known as Stop BEZOS. The bill, which Sanders introduced with Rep. Ro Khanna (D-Calif.) earlier this month, would require companies with more than 500 employees whose workers still need to access benefits like Medicaid and the Supplemental Nutrition Assistance Program to pay the government back, dollar for dollar.

And yes, that’s a reference to Jeffrey P. Bezos, founder and chief executive of Amazon.com, the world’s wealthiest man and owner of The Post. Sanders jokingly asked if talking about him during our interview would put my salary at risk. I assured him I’ll be okay.

In Sanders’s view, there is something wrong when “the wealthiest guy in the history of the world, worth about $155 billion, $160 billion … pays workers wages so low that many of them — we don’t know how many of them — are forced to go on public assistance, on food stamps, Medicaid and public housing.”

Amazon, as could be predicted, pushed back hard, saying Sanders’s claims were “inaccurate and misleading” because he did not differentiate between full-time, part-time and temporary employees. More surprisingly, many mainstream and left-leaning Democrats — both establishment figures and media pundits alike — derided it too, accusing Sanders of denigrating the government social safety net and promoting a policy that would make corporations less likely to support such programs and employ people who needed access to them. The Center on Budget and Policy Priorities, a left-leaning think tank, quickly published a paper tearing the proposal apart.

“That’s inside-the-Beltway push back, I would argue,” Sanders said. “My political gut tells me what we are proposing is wildly popular.”

He continued: “I ran for president. I was criticized for every bloody thing I did. Medicare-for-all. ‘Oh, it’s an impossible idea,’ right? ‘American people won’t support it.’ Last poll, 70 percent. ‘Oh public colleges and universities, tuition free, terrible idea.’ Sixty percent of American people support that idea, okay. ‘Raising the minimum wage, you’re crazy, you can’t double it.’ Overwhelming support for it.”

Sanders believes that will happen for Stop BEZOS, too.

“Is my legislation perfect? Probably not,” he said. “Of course, the establishment folks are going to attack us … That’s great. They can come up with better legislation. We’ll look forward to working with them.”

This is where we get to heart of the matter. Sanders and his detractors on the Democratic side are often talking past one other. On a policy level, it is helpful to think of what Sanders is doing as both offering a picture of how the world should be and jump-starting a conversation about how we should get there. To turn to a cliche, Sanders is discussing the forest of income inequality, while many Washington insiders, maybe out of habit, discuss the trees.

Take Social Security. Sanders is not wrong that expanding Social Security is a popular position. Earlier this year, Social Security Works, an advocacy group backing the Sanders effort, released a poll showing two-thirds of voters said they are more likely to vote for a candidate who says they will expand and increase benefits. Just this week, the advocacy group the National Institute on Retirement Security found that more than half of American workers have no money saved for their post-work lives.

Yet, one rarely hears that in Washington, where the conversation is forever about “saving” Social Security — by cutting back on benefits via such mechanisms as raising the age of retirement and changing the annual inflation adjustment to make it less generous.

In Sanders’s view, this demonstrates how the Washington establishment is disconnected from the concerns of American life — obsessing about the never-ending Washington horse race while ignoring the financial stress many Americans face. Money from the 1 percent seeking to influence the political process both causes and compounds that separation.

The result? Too many Americans live in financial desperation. “Are they living in freedom?” Sanders asks.

This brings us back to the STOP Bezos Act. It’s worth noting that Sanders’s overarching point about work and government benefits was not controversial on the left in the past. Those highlighting the poor quality of jobs in the retail and fast-food sectors have long made similar arguments. In 2014, the liberal Center for American Progress released a report arguing that raising the minimum wage to $10.10 would cut federal money spent on SNAP by $4.6 billion annually. That same year, Americans for Tax Fairness estimated that Americans subsidize Walmart, the nation’s largest employer, by paying out $7.8 billion in social welfare benefits to its employees annually.

It’s a common talking point in Britain, too. Last year, a parliamentary report accused gig-economy companies of “free-riding on the welfare state,” leaving “ordinary taxpayers [to] pick up the tab.” And earlier this month, shortly after Sanders announced his plan, Archbishop of Canterbury Justin Welby, the highest ranking member of the Anglican church, similarly argued that not paying workers a living wage was tantamount to “leaching” off the taxpayers.

Even if critics are right and Sanders’ bill is sloppy and rife with unintended consequences, it gets at an essential truth about our society: Few Americans want to work a 40-hour week and still need government help to get by, especially in a country where such benefits are often stigmatized.

Perhaps Sanders shouldn’t have named the act for Bezos (and I don’t say that because I am writing this piece for The Post). Bezos might indeed be the world’s wealthiest man, but Walmart employs multitudes more people than Amazon in the United States. In fact, one analysis last year by 24/7 Wall St. and Olivet Nazarene University found it is the largest private employer in 19 states. Meanwhile, the Communications Workers of America released a report earlier this year claiming 1 in 5 employees of American Airlines subsidiary Envoy Air turned to food stamps. Disney was recently the subject of yet another union-sponsored report claiming two-thirds of its employees at Disneyland Resort are “food insecure.”

Sanders knows all this — heck, he talks about it frequently — but the effect of naming the bill after Bezos means the majority of the attention is concentrated on one company.

There are also practical reasons to highlight the role of all the employers whose workers need to turn to the government to get by: These same social safety net provisions are under prolonged attack by the Trump administration. They have proposed cuts for both Medicaid and SNAP. The administration also gave four states permission to attach work requirements to Medicaid eligibility. In Arkansas, more than 4,000 people have been removed from Medicaid as a result. This could, in turn, increase the power of employers over employees and could force people who receive them to remain in low-paying jobs for fear of losing their benefits.

In many ways, the default on the left is still, even after the disaster that is President Trump, to emphasize the practical, often technocratic fixes over making the moral argument. It’s not wrong, but it doesn’t grab the popular imagination.

“The issues that I talk about are not going to create utopia in the United States of America,” Sanders said. “But what they will do is lift a lot of anxiety off the shoulders of working families. We need to force that discussion.”