Andrew Yang says he officially left the Democratic Party

• "My goal is to do as much as I can to advance our society. There are phenomenal public servants doing great work every day — but our system is stuck. It is stuck in part because polarization is getting worse than ever," Yang said.
• He said he has always been at odds with the Democratic Party: "I’m not very ideological. I’m practical. Making partisan arguments — particularly expressing what I often see as performative sentiment — is sometimes uncomfortable for me."
• "I’m actually more comfortable trying to fix the system than being a part of it."

The big picture: Yang's announcement comes a day before his book, "Forward: Notes on the Future of Our Democracy," is set to be released.

• According to its publisher, Crown, the book will introduce “us to the various ‘priests of the decline’ of America, including politicians whose incentives have become divorced from the people they supposedly serve.”

Between the lines: Politico reported earlier this month that Yang will be launching a third party this month.

Editor's note: This story has been updated with additional details.