Former interim Democratic National Committee Chairwoman Donna Brazile became a prominent topic on social media Thursday after dropping a bombshell about Hillary Clinton.

What did Brazile say?

Brazile admitted that she was shocked to discover how much the  Clinton campaign controlled the DNC long before the primary election determined who the nominee would be.

In an excerpt from her upcoming book, Brazile says she discovered a document that explained why the Clinton campaign had such a stranglehold on the DNC. It was published in Politico Thursday.

"When I got back from a vacation in Martha’s Vineyard," she wrote, "I at last found the document that described it all: the Joint Fund-Raising Agreement between the DNC, the Hillary Victory Fund, and Hillary for America."

The agreement—signed by Amy Dacey, the former CEO of the DNC, and Robby Mook with a copy to Marc Elias — specified that in exchange for raising money and investing in the DNC, Hillary would control the party’s finances, strategy, and all the money raised. Her campaign had the right of refusal of who would be the party communications director, and it would make final decisions on all the other staff. The DNC also was required to consult with the campaign about all other staffing, budgeting, data, analytics, and mailings.

Brazile goes on to explain that she believed the arrangement was not illegal, but definitely appeared unethical.

The funding arrangement with HFA and the victory fund agreement was not illegal, but it sure looked unethical. If the fight had been fair, one campaign would not have control of the party before the voters had decided which one they wanted to lead. This was not a criminal act, but as I saw it, it compromised the party’s integrity.

She said that she had promised Sen. Bernie Sanders (I-Vt.) to get to the bottom of whether Clinton controlled the DNC, and she called him on Sept. 8, 2016, to tell him what she had discovered.

What was the response?

While some praised Brazile for her supposed bravery for exposing the agreement, others excoriated her for waiting so long to expose alleged corruption in the Democratic National Committee.

Read @donnabrazile’s book excerpt if you haven’t already. If you’re a @BernieSanders supporter prepare to be angry https://t.co/Ff3ekmr4Jc

— Jake Tapper (@jaketapper) November 2, 2017

Huge: @donnabrazile accuses Clinton campaign of "rigging" the primary w/"internal corruption" & "unethical" finances https://t.co/XKR7eWCDOb pic.twitter.com/VlGajwF3Jd

— Glenn Greenwald (@ggreenwald) November 2, 2017

Wow @donnabrazile says Clinton did indeed stack the deck against Bernie with an unethical fundraising agreement https://t.co/tsGz3PDbwX

— Sam Stein (@samstein) November 2, 2017

Former Bernie Sanders surrogate Nina Turner thanked Brazile:

Oooooweeee! “You can put truth in the river 5 days after lie, truth gone catch.” -Grandma

Thank you @donnabrazile https://t.co/WKzjYc3c5K

— Nina Turner (@ninaturner) November 2, 2017

Brazile’s book, "Hacks: The Inside Story of the Break-ins and Breakdowns that Put Donald Trump in the White House," is expected to come out next Tuesday on election day.