Kennedy is “not remotely qualified,” said Peter Lurie, president of the Center for Science in the Public Interest, a group that, like Kennedy, has long pushed for greater regulation of unhealthy foods. “Nominating an anti-vaxxer like Kennedy to HHS is like putting a Flat Earther at the head of NASA,” Lurie added in a statement.

The vociferousness of the opposition from the left suggests Kennedy won’t be able to rely on Democratic votes in the Senate to get his nomination over the line. He could need some, given Republicans’ narrow majority and concern in the GOP caucus about Kennedy’s support for more environmental and agricultural regulation and for abortion rights.

Some, like Angela Huffman, president of Farm Action, a group that shares Kennedy’s views linking corporate food production practices to disease, hope for a productive relationship. She sees “great areas of opportunity” with Kennedy at HHS.

But most activists don’t share her optimism. They are worried that Kennedy could severely damage public health if he follows through on his pledge to fire hundreds of civil servants or uses his platform to spread misinformation about vaccines.

“You need to build a civil service that’s further immune from corporate influence but also political influence. RFK Jr.’s antipathy toward the medical and scientific establishment will put him in an adversarial relationship with the scientists” who work at HHS, said Jeff Hauser, executive director of the Revolving Door Project, a government watchdog group that shares Kennedy’s goal of rooting out corporate influence.

Protect Our Care, a left-of-center group that lobbies to protect Obamacare, which Kennedy would manage if he’s confirmed, is already moving to press senators to block him. The organization recently launched a “Stop RFK War Room” aimed at mobilizing grassroots opposition.

“This is someone whose views are so anathema to public health,” said Brad Woodhouse, the group’s executive director. “We want to create enough noise around why we think he shouldn’t be the HHS secretary that we either force Trump to withdraw him or defeat him.”

Public Citizen, the consumer advocacy group founded by Ralph Nader that has long decried pharma influence over drug approvals, as Kennedy has, called him “a clear and present danger to the nation’s health” who “shouldn’t be allowed in the HHS building, let alone placed in charge” in a statement after Trump nominated him.

The group’s co-president, Robert Weissman, told POLITICO he simply doesn’t believe Trump would allow Kennedy to crack down on corporate influence over the regulators.

“Whether it’s going to be overt or not, the deal for getting the nomination is not doing anything in [a progressive] direction,” he said.

Kennedy once had many allies on the left. A scion of one of America’s most famous Democratic families, groups he led helped clean up the Hudson River and protect it from pollution. Time magazine called him a “hero of the planet” in a 1999 cover story.

But his shift into anti-vaccine advocacy in more recent years, pushing the discredited claim that vaccines are dangerous and cause autism, had made him a pariah among establishment Democrats even before he sought the party’s nomination for president last year.

That distaste grew stronger this year when he decided to instead launch an independent presidential bid, and still more when he threw his support to Trump in August.

Kennedy also made enemies on the left in 2021 when he published a best-selling book painting the Biden administration’s response to the Covid pandemic as a conspiracy to enrich pharmaceutical companies. “You have to worry that he’s not going to make good decisions,” said Dr. Ashish Jha, who led the Covid response for President Joe Biden and now heads the Brown University School of Public Health.

No Democratic senators have said they’ll vote to confirm Kennedy. If he gets the HHS job, Democratic lawmakers aligned with him on issues like regulatory capture and environmental regulation suggested they would work with him toward common goals while also voicing concerns.

Sen. Elizabeth Warren (D-Mass.), for instance, said she would “do what I need to do” to advance her constituents’ interests, while also saying Kennedy “would be a real threat to public health.”

Sen. Cory Booker (D-N.J.) posted a video to X this week in which he delivered a script that sounded like something Kennedy would say, decrying unhealthy food. Kennedy thanked him. But Booker told POLITICO he’s skeptical that a Trump administration would work toward progressive goals around regulation of food ingredients and promotion of good nutrition.

That was a common concern among groups that share Kennedy’s views on food and its connection to disease — that Kennedy would not be able to overcome objections within his own party to policies advancing their shared goals, or navigate HHS’ massive bureaucracy given his lack of managerial experience.

“Oh my God, has he ever seen a Federal Register notice? Does he know what you have to do to write one of those?” wondered Marion Nestle, a professor at New York University and longtime critic of the nation’s food system who nonetheless hopes Kennedy can make some headway.

Colorado Gov. Jared Polis is a rare exception in his enthusiasm for Kennedy. He wrote on the social media platform X shortly after Trump named Kennedy that he was “excited” by the pick and that he was looking forward to “partnering with him to truly make America healthy again.”

Polis was roundly condemned by fellow Democrats.