Michael Bloomberg has spent hundreds of millions of dollars over the years to promote gun control laws and anti-gun candidates. So why are many gun control activists not only vocally backing other candidates, but bashing the anti-gun billionaire?

The South Florida Sun-Sentinel recently reported on several co-founders of the gun control group March For Our Lives who are ardently supporting the Bernie Sanders campaign, including Cameron Kasky, who regularly bashes the Bloomberg candidacy on social media.

It’s not just Kasky. Alex Wind, another co-founder of March For Our Lives, has also been speaking out against Bloomberg’s criticism of Sanders’ opposition to some gun control bills in years past, by noting that Bloomberg has his own history of funding candidates who received A+ ratings from the NRA.

Again, these are not pro-gun Democrats going after Bloomberg. They’re gun control activists who are ardently campaigning against the man who arguably has done more to advance their anti-gun agenda than any other American over the past twenty years.

Maybe this could be explained by the fact that the March For Our Lives founders are still very young, and Sanders is clearly the candidate of choice this cycle for Democrats under the age of 35. However, Sanders isn’t the only candidate that’s getting the support of gun control advocates over the anti-gun billionaire. There are also a number of Moms Demand Action volunteers and chapter leaders who are choosing to back Elizabeth Warren over Bloomberg, like these pro-gun control moms in Florida.

And New Jersey.

And Virginia.

This is not to say that every gun control activist is shying away from Bloomberg. Lori Haas, who’s daughter was wounded in the Virginia Tech shooting in 2007, has endorsed the candidate, and several other Moms Demand or Everytown members have also come out in public support. Still, Everytown itself, which is largely funded by Bloomberg, has taken pains to point out that they’re supporting any candidate who supports gun control. That means they’re supporting every candidate in the Democratic primary field at the moment.

Even if Bloomberg doesn’t have the formal endorsement of his own gun control group, he has something almost as good; it’s mailing list.

The leaders of Moms Demand Action state chapters and local groups received the news from Aimee Tavares, a senior national organizing director for the group, who sent an email roughly three and a half hours after news broke that Bloomberg would formally announce his candidacy. “Given his unique role in launching Everytown, his leadership in advancing the cause of gun safety, and the significant investments he’s made in helping to grow our movement, Mayor Bloomberg’s campaign is temporarily renting access to our list of supporters so they can communicate his plans for achieving our shared goal of a nation free from gun violence,” Tavares wrote.

Tavares added the campaign would not retain access to Moms Demand Action’s email list at the conclusion of Bloomberg’s bid. Members of the group would be “under no obligation to take any action” in response to Bloomberg’s campaign missives, and that “it is entirely up to our volunteers how they spend their volunteer time in this election and which candidates they choose to support, up and down the ballot,” she wrote.

Tavares’ email gave no endorsement of Bloomberg’s candidacy, but noted that “his participation will ensure that our issue remains at the forefront during the remainder of primary season.” In a Twitter thread announcing his candidacy, Bloomberg shared that he had “founded the largest gun safety group in history” alongside a photo of him posing with Moms Demand Action volunteers.

I don’t think Everytown for Gun Safety could endorse Bloomberg, honestly. Not without causing a major backlash within the organization. The move to co-opt the group’s email list to use for his campaign upset many members, and I’ve heard from more than one gun control supporter in recent weeks who’s expressed growing resentment over the billionaire’s actions. There are more and more grumbles that Bloomberg’s anti-gun activism over the years has been more about advancing himself and building his brand over the actual issues. If the organization came right out and endorsed his campaign, I think you’d see an outright revolt among members.

I think it’s newsworthy that the distaste for Bloomberg as a candidate runs so deep among many gun control advocates, given his financial largess in support of the movement over the years. Admittedly, I have my own anti-Bloomberg bias, but as news outlets that aren’t named after the candidate do their due diligence in reporting on him, this is an angle worth exploring.