On Tuesday, Democratic Texas Rep. Joaquin Castro, who chairs the presidential campaign of his twin brother Julian, tweeted the names and employers of more than 40 San Antonians who maxed out their donations to President Donald Trump’s reelection campaign.

Mind you, the federal maximum is $2,800 per individual, so we’re not talking about nefarious millionaires and billionaires or political activists or public figures. The congressman doxed a bunch of retirees and business owners whose only sin was displeasing Castro.

The congressman claims he is targeting voters who “are fueling a campaign of hate that labels Hispanic immigrants as ‘invaders.’” First of all, if Castro disagrees with his fellow Texans on whether illegal immigrants are “invaders,” he is free to try to change their minds. Instead he decided to sic every unhinged progressive activist in Texas on these businesses, which, one imagines, employ and serve plenty of people in his community that don’t even care about politics.

Then again, Castro has no clue if those he singled out support Trump’s rhetoric on immigration or even if they support his position on the borders. Maybe some of his victims maxed out because they’re happy with the unemployment rate or like GOP’s tax policy. Or maybe they see the election as a binary choice and prefer a demagogic president to a leftist congressman who feels comfortable doxing his own constituents? Who knows?

Not that it really matters, of course. I may believe that Castro is a lightweight authoritarian, it still doesn’t mean I should post his family’s business addresses on Twitter.

Democrats like Castro have adopted a political zealotry that rationalizes virtually any tactic they deem is necessary to fight Trump. This, I guess, now includes intimidation. The purpose of tweeting these names wasn’t merely to bully those who have already donated to Trump’s reelection, but to warn anyone in his district thinking about contributing to consider potential retaliatory public attacks on their businesses (or worse.)

Leftist groups have become quite adept at destroying the lives of those who back causes they dislike. Most notably there is the case of former Mozilla CEO Brendan Eich, who had the audacity to dissent from prevailing opinions in California. While Eich can weather such an event, I wonder what the Texans on Castro’s list will do if their businesses go under? All for the sin of expressing a political opinion.

It is true, as some readers will no doubt point out, that anyone could look up these names, as they are a matter of public record. That’s a problem, indeed. For one thing, campaign finance laws are meant to keep politicians honest, not to be used as Enemies Lists by politicians. But Castro, who has a far bigger megaphone than most, makes a strong case for expanding anonymity in political speech.

The obsession with transparency in campaign money is a byproduct of an obsession with controlling speech. The idea that citizens should be expected to report to the state before expressing their political opinions is un-American and undermines free expression.

“Anonymity is a shield from the tyranny of the majority,” the 1995 Supreme Court ruling in McIntyre v. Ohio Elections Commission famously noted, because it “exemplifies the purpose behind the Bill of Rights and of the First Amendment in particular: to protect unpopular individuals from retaliation…at the hand of an intolerant society.”

The intolerant force in this case is Castro.