"If this were a hostage situation, that letter would not qualify as proof of life," Ackman wrote.
"Every day, our President Joe Biden fights for the American people and we are deeply, deeply grateful for his service to our nation."
Biden claimed the series "intentionally manipulate[d] the facts" and tried to "dehumanize" him.
The revelations came ahead of Secret Service Director Kimberly Cheatle testifying before Congress on Monday.
Cheatle answered, "Yes, I do believe it was."
"I don't know the specifics."
"Vice President Harris has my full support. So Michigan, let’s get to work. We cannot let Donald Trump anywhere near the White House. Let’s go!"
The poll was conducted prior to Biden dropping out of the presidential race Sunday.
Biden reportedly had conversations with a number of close aides leading up to the decision to drop out indicating that he was open to ending to his campaign.
Loder has a history of violent extremism and has been permanently banned from the social media platform X, formerly Twitter, for inciting violence.
"Now more than ever, it is crucial that our party and country swiftly unite to defeat Donald Trump and the threat to American democracy. Let’s get to work."
“This might be the greatest fundraising moment in Democratic Party history.”
Frank Biden said that he is glad for “whatever time we have left.”
Sources close to Manchin said he had been considering the idea, per CNN.
One-third of Democrat respondents in the poll agreed with the statement, “I wish Trump’s assassin hadn’t missed.”