New Jersey Sen. Cory Booker was trying to walk to the men’s bathroom Tuesday afternoon when about 30 immigration activists surrounded him to offer their thanks. Booker had just vowed to testify against Alabama Sen. Jeff Sessions, a longtime immigration hard-liner, at the attorney general nominee’s confirmation hearing — something no senator had ever done to a colleague.

Progressives cheered the decision. When Booker followed through the next day and denounced Sessions’s record on race, many left-leaning voices were ecstatic:

Applauding @CoryBooker, first sitting Senator to testify against fellow sitting Senator. Will oppose #JeffSessions. https://t.co/3R2JFAYvfV — Ava DuVernay (@ava) January 10, 2017

But by Thursday, the story about Booker had flipped. The New Jersey senator and 12 other Senate Democrats had joined the bulk of the Republican caucus to kill a proposal aimed at lowering prescription drug prices. What made Booker’s vote all the more anguishing for the left is that the proposal won the backing of 13 Republican senators, and had a real chance of passing.

The recriminations came quickly. “This is classic Booker — stand out front on feel-good social issues, regardless of his past positions, and align with big money everywhere else,” wrote Walter Bragman at Paste Magazine.

Booker has long faced criticism on the left for cultivating the elite financial ties that much of the Bernie Sanders wing despises. And while it’s true that his vote may have had more to do with the concentration of the pharmaceutical industry in his home state, it’s also only served to confirm some progressives’ suspicions that he’s too closely allied with corporate interests in the Democratic Party.

An attempt to rein in out-of-control drug prices goes down

It didn’t help Booker that the amendment he voted against was co-sponsored by the best-known progressive in the Democratic Senate caucus: Bernie Sanders.

On Wednesday, Sanders and Minnesota Sen. Amy Klobuchar put forward a proposal during what’s known in Capitol Hill parlance as a “vote-a-rama.” Because of a quirk in congressional procedure, senators were allowed to offer hundreds of proposed changes to the budget resolution Republicans want to use to repeal Obamacare.

The Sanders-Klobuchar proposal would have allowed Americans to buy prescription drugs from Canada, where they are significantly cheaper.

“[The Canadians] pay 50 percent less for the same exact medicine that we buy in Vermont or in America. We know why: The power and wealth of the pharmaceutical companies have bought the United States Congress,” Sanders said.

EpiPens, for instance, cost twice as much in the US as in Canada. The depression drug Abilify is more than six times as much in the US as in Canada. Drug companies have scored record profits as the cost of prescription drugs has soared year over year by about 18 percent, according to the Huffington Post.

As Dylan Matthews explained at the Washington Post in 2013, the kind of amendment put forward by Sanders and Klobuchar was mostly symbolic — it would not have actually legalized prescription drug importation from Canada. But if passed, it would have signaled that there’s enough political support in the Senate for the idea, increasing the odds of some real action eventually being implemented.

It’s an idea that has broad public support. One poll found 72 percent of Americans support importation. As the Intercept notes, Trump campaigned on a similar pledge, and on Wednesday he accused the pharmaceutical companies of “getting away with murder” — a quote Sanders then read from the Senate floor.

Why do Americans pay so much more than Canadians for prescription drugs? Because the pharmaceutical industry has bought the US Congress. pic.twitter.com/Si8q8otWj5 — Bernie Sanders (@SenSanders) January 12, 2017

“The time has come for us to stand up to the drug companies,” Sanders said.

It wasn’t to be, as the amendment failed narrowly by a 46-52 margin.

In an email, Booker’s spokesperson cited concerns over the “safety standards” of the prescription drugs that would be coming in from Canada under the amendment. As both the New Republic and the Intercept have noted, that explanation is somewhat hard to believe — the drugs sold in Canada are often literally produced in America, and Canada doesn’t seem to have a particular problem with poisoned medicine.

The backlash to Booker, building for a long time

Thirteen Democrats broke ranks with their party to defeat the Sanders-Klobuchar amendment. But the ensuing outcry from the left has been particularly concentrated on Booker, a national media star widely seen as a possible 2020 presidential candidate.

The Huffington Post accused Booker and the other defecting Democrats of “doing the industry’s bidding.” Jezebel noted that he had “completely disregarded overwhelming national sentiment” and that he was setting up Democrats “for a massive failure.” After asking why Booker would vote for an uncontroversial proposal, Slate’s Helaine Olen more or less settles on the conclusion that it must have been the campaign contributions.

Jezebel reported that Booker received $267,338 from pharmaceutical companies, which led some on the left to say that this money explained his vote.

Glad @Jezebel covered this, tho it's weird the hed includes "For Some Reason," when the blog makes the reason clear https://t.co/usQihPTbp7 pic.twitter.com/YTMK1Tf7os — Jesse A. Myerson (@JAMyerson) January 12, 2017

“[Booker’s] decision to violate Senate norms is admirable,” wrote Sarah Jones at the New Republic of his speech against Sessions. “But his rejection of the Sanders-Klobuchar proposal is the latest entry in a legislative record that should worry progressives.”

Indeed, as Jones notes, no senator has raised more money from Wall Street than Booker. In 2012, then mayor of Newark, Booker memorably criticized President Obama for going after Mitt Romney’s record at Bain Capital — calling the attacks on private equity “ridiculous” and “nauseating.” He’s worked closely with Facebook’s Mark Zuckerberg and education reformer Michelle Rhee on improving Newark’s schools — a decision that’s been criticized by some for allowing private industry to influence public schools.

Neoliberals are the new political pariah: "Cory Booker And A Bunch Of Democrats Prove Trump Right On Big Pharma" https://t.co/egTOBglfkC? — Nomiki Konst (@NomikiKonst) January 13, 2017

Some think these hits on Booker have been overblown. In 2013, the Atlantic’s Molly Ball argued that the left was picking fights with Booker over meaningless cosmetic issues, and that Booker really is solidly progressive.

“Booker's allies find it perplexing that normal politician activities, like raising money and being ambitious, are seen as uniquely damning in his case,” she writes. “They insist that he is sincerely motivated by issues of inequality and social justice ... [and] that the hobnobbing with billionaires, the Twitter stunts, the television talk-show appearances, are all aimed at attracting attention for his causes and investment in his city.”

Whatever its merits, this backstory has primed many on the left to see a story about a Booker vote on big pharma through the lens of his corporate connections. And they see the stakes here as being much bigger than just Booker — a lot of the problems in Booker’s record speak to the same problems Sanders has identified with both Clinton and the “corporate wing” of the Democratic Party more broadly.

Booker, like all senators, voted to protect his home state’s interests

The irony of this backlash is that it actually doesn’t make a lot of sense to see Booker’s vote on the pharmaceutical amendment as a direct result of the money that’s been poured into his campaign war chest.

Instead, the much simpler explanation is that Booker was following the predictable, longstanding pattern of elected officials to try to protect the jobs and industries that dominate their home states.

“Almost any member of Congress from New Jersey — either a senator or House member, no matter how liberal or conservative — will be fiercely protective defense of pharmaceutical industry,” says Ross Baker, a political scientist at Rutgers University.

Just compare the vote totals with the industry’s contributions. The senator who received the most money from the pharmaceutical industry since 2010 is Arizona Republican John McCain, who received $1.2 million in campaign contributions. McCain voted for the Sanders-Klobuchar amendment. Pharma has donated $800,000 to Iowa Republican Chuck Grassley — who also voted for the amendment.

Similarly, the Democrat who has received the most from the pharmaceutical companies, according to OpenSecrets, is Senate Minority Leader Chuck Schumer. But Schumer, like McCain, also voted in favor of the Sanders-Klobuchar amendment. Oregon Sen. Ron Wyden has received more than $600,000 from pharmaceutical companies — more than three times that received by Booker — and also backed the amendment. (So did Ohio’s Sherrod Brown, who received two times as many donations as Booker.)

The pharmaceutical industry has a “massive” presence in New Jersey, Baker says. It’s almost unheard of for a New Jersey politician to go against pharmaceutical companies — it’d be like a politician from Maine arguing for onerous new regulations on fisheries, or an Iowa Republican voting against ethanol subsidies.

The vote on the pharmaceutical amendment alone shows that the phenomenon is hardly limited to Booker. Washington state Sens. Patty Murray and Maria Cantwell — among the more progressive members of the caucus — voted against the proposal.

Meanwhile, Democratic moderates like Michigan’s Gary Peters and Virginia’s Tim Kaine voted for it. Peters and Kaine are hardly more “progressive” than Murray and Cantwell — but they represent states that do not host a heavy concentration of pharmaceutical companies.

The Senate has not caught up to the growing nationalization of politics

The fight over Booker’s vote highlights a real, and much broader, disconnect between Capitol Hill and the outside world.

On the one hand, members of Congress have continued to legislate as they always have — with a far greater concern for the jobs and markets in their own states.

But that reality isn’t always reflected in a media environment that increasingly sees everything through its implications for the country as a whole. In part, that’s because of the long decline in the size and staffing of local newsrooms, says Michele Swers, a Georgetown University professor who specializes in Congress. And in part it’s because people have stopped caring nearly as much about politics of their states, as research by political scientist Jonathan Ladd has shown.

“Politics is much more nationalized than it was just a few decades ago,” said Swers in an interview in October 2016.

She added: “That probably has to do with the fact that the way you get your information has changed. Twenty years ago ... if you were a House member, you could get the coverage of your character, of the bill you passed for your home district, or of you in parades or whatever. Now, with there being so much more national coverage and the local papers dying out, it’s much more ideological.”

And that new dynamic will create a new form of headache for senators like Cory Booker who may have higher national ambitions. They are stuck between two bad outcomes — defying the industries of their home states, or taking a position that could be broadly unpopular with their national parties.

Soon we’ll get another test of whether this calculus is beginning to change within the halls of Congress. Sanders is expected to soon introduce similar legislation to the drug prescription bill that was defeated on Wednesday. If Booker changes his position, it could be a big sign that the grassroots is winning.