Hundreds lined up outside the Union Square Barnes & Noble Tuesday morning for Hillary Clinton to sign their copies of her book, "Hard Choices," which went on sale Tuesday.

"I want her to run for president," said Marilyn Moorcroft, 71, of the West Village. "She will be a terrific president."

The orderly line stretched along East 17th St. and around the corner to Park Avenue South for the 11 a.m. signing.

While Clinton has yet to declare whether she's running for president in 2016, most in line - some wearing buttons saying "I'm ready for Hillary" - were clearly hoping she'd throw her hat in what will likely be a very crowded ring.

Joe Cassar, 62, a retired insurance executive from Murray Hill, sees Clinton's book tour as a start to her presidential run.

"Of course this is a campaign," he said. "I'm a Democrat. I want to see what her positions are and where she stands."

And if given the opportunity to pose a question to Clinton at the book signing, Cassar said he'd ask if she'd continue Obamacare and whom she'd pick for her cabinet.

Maria Karidis, 37, of Astoria said she’d ask the former secretary of state, “what can you do to help the Greece economy?”

Not the U.S. economy?

“Corporations already own the United States,” Karidis responded.

Workers for readyforhillary.com were soliciting admirers to sign up as volunteers for a Hillary Clinton presidential campaign. “So far, I’ve got four pages of names,” said intern Nico Bonder.

Her candidacy “is a fait accompli at this point,” observed Marc Fenton, 49, a freelance life coach who lives in Union Square. Fenton, who uses a motorized scooter, was a bit miffed by the exacting security protocols to see the former first lady. (Wristbands for entry, book purchase required, all personal items surrendered, etc.)

“Eight years ago, to see (Barack) Obama, it was very straight forward,” and he was allowed to go to the front of the line, he noted. “Obama walked into the room, noticed me on my scooter and shook my hand before he greeted anyone else,” recalled Fenton, who wondered if he would be accorded the same courtesy by this potential presidential candidate.

The crowd was full of Democrats, but not everyone in line was a die-hard Hillary fan.

M. Saidia McLaughlin, 63, a retired educator from “the proud Republic of Brooklyn” popped by after not being able to find “Hard Choices,” at The Strand bookstore nearby. While she would support Clinton should she become the Democratic nominee, McLaughlin said Elizabeth Warren and Maria Shriver topped her list of preferred candidates.

The Clintons, she said, “threw a lot of women under the bus,” such as legal professor Lani Guinier, whose nomination for a federal civil rights post was withdrawn by then-President Bill Clinton, and ex-surgeon general Dr. Joycelyn Elders, who Bill Clinton fired after speaking frankly about  contraception, masturbation and legalizing drugs.

“Even the women in the welfare program! I’d ask her how did she let her husband marginalize women?”  McLaughlin said.

Zarine Ali, 32, a geology graduate student at Brooklyn College, said she was hoping to get a signed copy of Clinton’s book to give to her 5-year-old niece. “She’ll take New York for sure,” Ali said of the primaries. Clinton “has really proven herself,” as a politician and deserves a crack at being president, said Ali.

Coming to the book signing was a way for Ali to show her support. Clinton, she postulated, “probably wants to see how many people show up,” to gauge her likelihood of winning.

A political expert says the book signing was strategic

Hillary Clinton's White House plans may still be a mystery, but a political expert said the book signing in Union Square was a perfect strategic first move for a possible presidential bid.

Andrew Moesel, a political strategist for Sheinkopf Communications, said the Barnes & Noble event gave the former New York senator a great opportunity to get some spotlight.

“This is straight out of the political playbook, no pun intended,” he said. “A book allows for an incredible amount of public relations exposure and a widespread opportunity to meet potential voters, all under the auspices other than a political campaign.”

Starting in New York rather than some of the other contested political grounds like Iowa and Ohio, would help her finances and remind people about her political roots, according to Moesel.

The strategist said New York City is “the ATM for the U.S.” when it comes to political campaigns and Tuesday's large gathering at the book store will send a message to future donors that she still is popular among voters.

“Continuing to remind New York voters and Manhattan residents that she cares about their issues and putting in face time in the community can only help with fundraising down the road,” he said.

Moesel added that the city’s large liberal population will help to add more supporters and future volunteers to her potential 2016 bid.

“Galvanizing the support of people in Manhattan will help her to continue to shore up the left side of the political spectrum,” he said.

-Ivan Pereira