When U.S. Rep. Joaquin Castro apparently tried to shame more than 40 prominent San Antonians for donating money to President Trump, he also seems to have alienated some individuals who gave to Castro and his twin brother as well.

Joaquin Castro, who has been serving in Congress since 2013, is the brother of Julian Castro, a former San Antonio mayor and Obama Cabinet member who is seeking the 2020 Democratic presidential nomination.

“Sad to see so many San Antonians as 2019 maximum donors to Donald Trump," Joaquin Castro tweeted Monday, listing the Twitter handles of several owners of local businesses. “Their contributions are fueling a campaign of hate that labels Hispanic immigrants as ‘invaders.’”

JOAQUIN CASTRO FACING BACKLASH FROM ALL SIDES FOR POSTING TRUMP DONOR INFORMATION

Now the Washington Free Beacon is reporting an additional Trump donor also contributed to Castro's congressional campaign and The Washington Examiner found a third as well as three others listed in the tweet who made contributions to his brother's mayoral campaign, according to FEC records.

Philanthropist and former Valero Energy CEO William Greehey donated at least $10,000 to Joaquin Castro's congressional campaigns between 2011 and 2013, the Free Beacon reported. Businessman Gregory Kowalski, who was also listed, gave $1,421 to Castro's campaign in 2011.

"It is just amazing to me that he would do that. ... Then he's calling me a racist because I'm supporting Trump. I mean, this is just ridiculous.” Greehey told the Examiner. “There's a lot of things you don't like about the president and his tweeting, but here Castro is doing the same thing with his tweeting.”

"He's calling me a racist because I'm supporting Trump. I mean, this is just ridiculous." — Valero Energy CEO William Greehey, who reportedly donated to both Trump and Joaquin Castro

Edward Steves, owner of a manufacturing company, said he hosted a fundraiser at his house for Julián Castro's mayoral bid that raised more than $300,000. Donald Kuyrkendall, president of a San Antonio-based real estate company, also contributed to the mayoral campaign.

“Were his intentions to incite people to picket Bill Miller's barbecue or to come to Don Kuyrkendall’s house, you know, assault my wife, make nasty comments?” Kuyrkendall asked, according to the Examiner. “I'm just hopeful that none of this gets serious and that my grandchildren and children will be not intimidated by this stuff.”

“I'm just hopeful that none of this gets serious and that my grandchildren and children will be not intimidated by this stuff.” — Donald Kuyrkendall, past donor to Julian Castro

Another Julián Castro donor, retired real estate CEO Ed Kelley, told the Examiner he considers the former HUD secretary as a friend, but that his brother's tweet "did not leave a good taste in my mouth."

Previously, Fox News previously reported that Wayne Harwell, owner of a local real estate development company whose name appeared on Castro's list, donated money to Castro’s congressional campaign. But Harwell suggested that after Castro's Twitter message, he won't be supporting Castro anymore.

“I was also on a list of people that gave to Castro and if he dislikes me enough that he wants to put my name out there against Trump, I’m not going to give money to him,” Harwell told Fox News. “Obviously Castro feels pretty strongly against me.”

According to Federal Election Commission records, Harwell donated $1,000 to Castro’s campaign in September 2011.

“I’m pretty independent, but I support Trump,” Harwell explained.

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Joaquin Castro has remained defiant amid the widespread backlash and dismissed the criticism since what he posted was "public" information. He said Wednesday morning that it wasn't his "intention" for anyone to be harassed and that he "didn't create the graphic" but only "shared it."

Several GOP lawmakers -- including House Minority Leader Kevin McCarthy, R-Calif.; House Minority Whip Steve Scalise, R-La.; and Sen. Ted Cruz, R-Texas -- as well as members of the press condemned the tweet, calling it "dangerous."

President Trump reacted to the controversy Wednesday evening, blasting both Castro brothers on Twitter.

"I don’t know who Joaquin Castro is other than the lesser brother of a failed presidential candidate (1 percent) who makes a fool of himself every time he opens his mouth," Trump tweeted. "Joaquin is not the man that his brother is, but his brother, according to most, is not much. Keep fighting Joaquin!"

Fox News' Brooke Singman and Ronn Blitzer contributed to this report.