The prosecution's star witness, former Trump attorney Michael Cohen, called today's verdict "an important day for accountability and the rule of law."

"While it has been a difficult journey for me and my family, the truth always matters," he said.

Two senior Trump advisers who ABC News spoke with were extremely angry after the verdict.

Both said they were not surprised by the jury’s decision. One said, "The fix was always in," and the other added, "Not surprised -- it’s New York."

Donald Trump Jr., reacting to his father's guilty verdict, said, "The Democrats have succeeded in their yearslong attempt to turn America into a third-world s---hole. Nov. 5 is our last chance to save it."

The guilty verdict shows "no one is above the law," a representative for President Joe Biden's campaign said, adding, "But today's verdict does not change the fact that the American people face a simple reality. There is still only one way to keep Donald Trump out of the Oval Office: at the ballot box."

"Convicted felon or not, Trump will be the Republican nominee for president," Michael Tyler, communications director for the Biden-Harris campaign, said in a statement.

"A second Trump term means chaos, ripping away Americans' freedoms and fomenting political violence -- and the American people will reject it this November," Tyler said.

The White House offered a very brief comment, with a White House Counsel’s Office spokesperson saying, "We respect the rule of law, and have no additional comment."

Among the congressional response, Speaker of the House Mike Johnson, who traveled to Manhattan days ago to support Trump at the trial, said in a statement, "Today is a shameful day in American history. Democrats cheered as they convicted the leader of the opposing party on ridiculous charges, predicated on the testimony of a disbarred, convicted felon."

"President Trump will rightfully appeal this absurd verdict -- and he WILL WIN!" Johnson said.

Former President Donald Trump's campaign is already fundraising off of the guilty verdicts in his hush money trial, telling his supporters he has been convicted in a "rigged" trial.

"I was just convicted in a RIGGED political Witch Hunt trial: I DID NOTHING WRONG!" a fundraising email said. "They’ve raided my home, arrested me, took my mugshot, AND NOW THEY’VE JUST CONVICTED ME!" the email continues.

The email links to a fundraising page, in which Trump told his supporters, "I'm a political prisoner!"

The jury heard a readback of David Pecker's testimony about Donald Trump dating the "most beautiful women," the National Enquirer's coverage of Bill Clinton's "womanizing," and the "mutually beneficial" relationship between the tabloid and the Trump campaign.

Q: Can you explain to the jury how the topic of women in particular came up?

A: Well, in a presidential campaign I was the person that thought that there would be a number -- a lot of women come out to try to sell their stories, because Mr. Trump was well-known as the most eligible bachelor and dated the most beautiful women. And it was clear that based on my past experience, that when someone is running for a public office like this, the -- it is very common for these women to call up a magazine like the National Enquirer to try to sell their stories. Or I would hear it in the marketplace through other sources that stories are being marketed.

Q: Did you have or express any ideas about how you may be able to help kind of deal with those stories by women?

A: All I said was I would notify Michael Cohen.

Q: What about Bill and Hillary Clinton, did their names up during this meeting?

A: Yes.

Q: Can you explain how?

A: As I mentioned earlier, my having the National Enquirer, which is a weekly magazine, and you focus on the cover of the magazine and who -- and who and what is the story that is the topic of the week, the Hillary running for president and Bill Clinton's womanizing was the biggest, one of the biggest sales I had for the National Enquirer and the other tabloids, that's the other things that the readers wanted to read about and that's what I would sell weekly. So I was running the Hillary Clinton stories. I was running Hillary as an enabler for Bill Clinton, with respect to all of the womanizing. And I was -- it was easy for me to say that I'm going to continue running those type of stories for the National Enquirer.

Q: And did you believe that that would help Mr. Trump's campaign?

A: I think it was a mutual benefit. It would help his campaign; it would also help me.

The jury also heard the testimony where Pecker testified that he never purchased stories to kill for Trump prior to the 2016 election.

Q: And what was the purpose of notifying Michael Cohen when you came upon stories like that?

A: Well, as I did in the past, that would be in the past eight years, when I notified Michael Cohen of a story that was a negative story, he would try to vet it himself to see if the story was true or not. He would go to the individual publication to get the story to make sure the story wasn't published and getting killed.

Q: Prior to that August 2015 meeting, had you ever purchased a story to not print it about Mr. Trump?

A: No.