The lawmakers argued that publishing donor lists suppresses free speech and the right to freely associate.
“By publishing a list of private citizens who donated to his political opponent, Rep. Castro sought to encourage harassment against those citizens simply on the basis of their political beliefs,” they wrote. “It cannot be fairly argued that Rep. Castro had any other purpose in posting that list and telling his activist followers that those individuals were inciting hate. Whether he intended to provoke physical violence or merely verbal harassment, his intent was to chill the free speech and free association rights of Americans.”
On Monday evening, following that weekend’s mass shooting in El Paso, Texas, Castro tweeted the names of 44 Texans who donated the maximum $2,700 to Trump, specifically calling out the owners of several prominent businesses in San Antonio, where the Castro brothers are from.
Federal candidates are required to disclose the names and employers of donors who contribute $200 or more in Federal Election Commission filings, which are publicly available online.
However, it is unusual for a lawmaker to publish the names and business interests of individual donors of another campaign.
“Their contributions are fueling a campaign of hate that labels Hispanic immigrants as ‘invaders’,” Castro tweeted.
At the time, there were reports that the suspected gunman had allegedly posted a manifesto online shortly before the attack that included anti-immigrant rhetoric and warned of a “Hispanic invasion.”
The suspect has since reportedly told police that he carried out the shooting and that he was targeting “Mexicans.”
Julián Castro defended the tweet after Trump blasted the move.
“Joaquin and I will keep fighting. The American people will fight every day for our nation, against your hate, your corruption, and your ego. And we’ll win. #AdiósTrump,” he tweeted.