Donald Trump. File

Michael McGough, Tribune News Service

On Monday, Rep. Joaquin Castro, a Democrat who represents part of San Antonio in Congress and whose twin brother, Julian Castro, is running for president, tweeted out a list of 44 San Antonians who had made the maximum allowable donations to President Trump›s reelection campaign.

“Sad to see,” Castro tweeted, arguing that the campaign contributions “are fuelling a campaign of hate that labels Hispanic immigrants as ‘invaders.’”

Republicans, as they say, pounced.

“Democrats want to talk about inciting violence? This naming of private citizens and their employers is reckless and irresponsible,” Trump campaign communications director Tim Murtaugh said. “He is endangering the safety of people he is supposed to be representing.”

The president’s son, Donald Trump Jr., compared Castro’s tweet to the list of targets supposedly made in high school by the man accused of killing nine people in Dayton, Ohio, on Sunday. House Minority Leader Kevin McCarthy (R-Calif.) called Castro›s tweet «shameful and dangerous.»

Castro rightly responded that no one was “targeted or harassed” in his Twitter post. He also noted that the identities of donors are public information and that he didn’t list the donors’ addresses or telephone numbers. (He did include some of the donors› Twitter handles.)

Castro said the point of naming names was to “lament” that people in the San Antonio area were making contributions that “fuel hate.” Even if you think his real purpose was to shame Trump supporters, that’s still a far cry from inciting violence against them or subjecting them to the sort of incendiary language the president has used against immigrants.

Unlike the secret ballot, contributions to campaigns are a matter of public record — and for good reason. As the Supreme Court has recognised, disclosure serves the government’s interest in providing the electorate with information about the sources of election-related funding.

Inevitably, the privacy of donors is collateral damage. Contributors are stuck with the public knowing their identities unless they can show a reasonable probability that disclosure of their names would subject them to what the court called “threats, harassment or reprisals from either government officials or private parties.” That’s a high bar, and it doesn’t seem that the Trump donors called out by Castro could clear it.

In a 2010 opinion, the late Justice Antonin Scalia — noting that the secret ballot didn’t take hold in the United States until 1888 — seemed to dismiss the idea that Americans have any right to secrecy in the exercise of their civic responsibilities. He wrote: “Our nation’s longstanding traditions of legislating and voting in public refute the claim that the 1st Amendment accords a right to anonymity in the performance of an act with governmental effect.”

But even if Castro was within his legal rights in posting the names of local Trump donors, was this act of public shaming fair? Citizens contribute to candidates for a variety of reasons.

Perhaps some of the Trump donors from San Antonio support the president not because of his trashing of immigrants but because of his trade or national security policies, or simply because he will be the Republican Party›s nominee.

To which Castro could plausibly reply: “This is not a normal president and 2020 will not be a normal election. To support Trump (for whatever reason) is to support his campaign of hate.” It’s a hard argument to refute.