Many Democratic presidential candidates who vowed to reject lobbyist money from their campaigns were quick to throw their support behind Democrat Jaime Harrison, a well-connected former corporate lobbyist running to unseat Republican senator Lindsey Graham in South Carolina.

Harrison formally launched his Senate campaign on Tuesday and has already been endorsed by the party establishment. He began his career working for Rep. Jim Clyburn (D., S.C.) but left in 2008 to join the now-shuttered Podesta Group, at the time a Democratic lobbying powerhouse where he advanced the interests of coal companies, tobacco companies, and casinos.

Harrison's clients over the years included Wells Fargo and Bank of America, private equity firms Avenue Capital and Berkshire Hathaway, and pharmaceutical giants like Novo Nordisk and Merck. Also represented by Harrison over the years were Walmart, BP, Boeing, Lockheed Martin, and Google.

Democratic presidential candidates have shunned lobbyists; Sen. Cory Booker (D., N.J.), for example, has pledged to not take a dollar from lobbyists. But he had no hesitation backing Harrison.

"Jaime, I am so incredibly proud of you," Booker wrote just after his announcement. "I know your heart, and I know you will make a great U.S. Senator."

Jaime, I am so incredibly proud of you. We've known each other for more than two decades. I have admired your dedication to community, to meeting people where they are. I know your heart … and I know you will make a great U.S. Senator. #JoinJaime https://t.co/93cM31FWfs — Cory Booker (@CoryBooker) May 29, 2019

Former vice president Joe Biden, the current frontrunner in the primary, has also sworn off lobbyist money for his current campaign. He said, "South Carolina would be lucky to have" Harrison representing it.

South Carolina would be lucky to have @harrisonjaime representing them in the Senate. He has the character, intelligence, and integrity needed to serve his community well. I hope you'll #JoinJaime. https://t.co/Nal3ctZ06A — Joe Biden (@JoeBiden) May 30, 2019

South Bend mayor Peter Buttigieg, who was pushed to return lobbyist cash he'd already raised and pledge not to take any more of it, also rushed to support Harrison, saying the former lobbyist would be a "positive change" in Congress.

Similar endorsements have come from Julian Castro, who has pledged to reject lobbyist money, and New York City mayor Bill de Blasio, who has also taken an anti-lobbyist stand.

In addition to 2020 Democrats endorsing Harrison on Twitter, many of the same Democrats were cohosts of a D.C fundraiser for Harrison two weeks ago, according to an invitation obtained by McClatchy. Cohosts included many 2020 Democratic candidates vying for traction in the critical early primary state of South Carolina, such as senators Cory Booker of New Jersey, Michael Bennet of Colorado, and Amy Klobuchar of Minnesota, along with representatives Seth Moulton of Massachusetts, Tim Ryan of Ohio, and Eric Swalwell of California.

Harrison did not respond to an inquiry into whether any candidates discussed his lobbying background before endorsing him.

His lobbying work did raise eyebrows during his unsuccessful 2017 run to be chairman of the Democratic National Committee, but he defended his decision to enter lobbying as one he needed to make to take care of his family.

"You don't have very many options when you graduate from law school with $160,000 of student loan debt and want to take care of your grandma," he said at the time. "That is how I take care of my family."