The campaign of Democratic Rep. Joaquin Castro of Texas has publicized a list of San Antonio-area residents and businesses who donated the maximum amount to President Trump’s reelection effort, drawing accusations from the Trump campaign and numerous Republicans and conservatives of doxxing, attempted intimidation or worse.

“Sad to see so many San Antonians as 2019 maximum donors to Donald Trump — the owner of @BillMillerBarBQ, owner of the @HistoricPearl, realtor Phyllis Browning, etc.,” Mr. Castro’s campaign account tweeted. “Their contributions are fueling a campaign of hate that labels Hispanic immigrants as ‘invaders.’”

The listing provided not only the names, but also the workplaces of the donors — prime information for what has become known as “cancel” campaigns or the “doxxing” of people’s private lives.

Mr. Castro is not only the brother of faltering Democratic presidential candidate Julian Castro, but also his campaign chairman.

In all, the campaign publicized 44 Trump donors from the San Antonio area. The Trump campaign said Mr. Castro was making them targets of partisan revenge.

“At the very least, @Castro4Congress is inviting harassment of these private citizens,” tweeted Trump campaign communications director Tim Murtaugh. “At worst, he’s encouraging violence.”

Mr. Murtaugh asked, “Will media concerned about ‘rhetoric’ care about this? He’s listing people and their employers. This is a target list.”

Other Republicans furiously denounced the action, noting that Democrats regularly denounce the GOP as complicit in harassment and actual violence based merely on rhetoric and political criticism.

Both of Texas’ U.S. senators called on Mr. Castro to remove the tweet at a time of heated partisanship.

Sen. John Cornyn called the target list “grossly inappropriate” and Sen. Ted Cruz said, “Everyone needs to tone the hateful partisan rhetoric way down. This is wrong & Castro should retract it … elected representatives should not be vilifying & doxxing their own constituents.”

And a lawmaker with personal experience of politics-motivated violence joined the criticism.

“People should not be personally targeted for their political views. Period. This isn’t a game. It’s dangerous, and lives are at stake. I know this firsthand,” said House Minority Whip Steve Scalise, Louisiana Republican.

Mr. Scalise was among four people shot in 2017 at a Republican baseball practice by a former Bernard Sanders volunteer who yelled, among other things, that “this is for health care.”