After seventeen people were killed in a Parkland, Florida school shooting, Republican donor Al Hoffman Jr. announced that he will not donate to electioneering groups or candidates unless they support an assault weapons ban. Hoffman’s ultimatum goes against the conventional GOP stance of considering any new gun control measures anathema.

Alexander Burns of the New York Times reported that the Florida-based donor, a retired real estate developer and former ambassador to Portugal, sent Republican leaders like Jeb Bush and Florida governor Rick Scott an email that read, in part, “I will not write another check unless they all support a ban on assault weapons. Enough is enough!” Hoffman also made clear that he wouldn’t back Scott, who may run for Senate this year and who said, in the wake of the 2016 Pulse nightclub shooting, “The Second Amendment didn’t kill anybody.”

Hoffman has given millions to Republican causes and candidates, including $25,000 to the Mitch McConnell-aligned Senate Leadership Fund in 2017 and more than $1 million to the super PAC Right to Rise, which backed Jeb Bush’s presidential campaign. Hoffman also told the Times that he planned to reach out to “every single donor I know in the Republican party” and ask each one to join his boycott.