Hillary Clinton was talking politics on Primary Day on Tuesday, but it had nothing to do with the race for mayor.

Her new book "What Happened" focuses on her 2016 election loss. She signed books in Union Square and drew long lines of fans.

"I want to really know what Hillary's perspective of the campaign from her personal side was, because it's one thing for us to see it on TV and hear the debates and the rallies, but it's another thing for her to speak of what it was like on the inside," said one person waiting in line.

"I think she has a right to have a personal opinion, and make that personal opinion known. I appreciate the fact that she is showing us her private self, rather than her public self," noted another.

Clinton's book just hit store shelves Tuesday.