Throughout this primary season, Hillary Clinton has had a surprising surrogate at City Hall. No, it is not the mayor. It has been Melissa Mark-Viverito. NY1's Courtney Gross has more on how the City Council Speaker has become one of Clinton's most vocal cheerleaders.

One would think it would be the former campaign manager for Hillary Clinton's first Senate race.

But it's another occupant of City Hall who has proved to be her more aggressive — and visible — ally.

"She is really taking on issues that matter to me personally," the council speaker said.

Almost two months before Mayor Bill de Blasio endorsed his old boss for president, Melissa Mark-Viverito endorsed Clinton in September of last year. And since then, she has been an ever-ready surrogate to boost the Clinton campaign.

She helped launch the group Mujeres for Hillary and traveled to three states stumping on her behalf.

From a rally in Las Vegas, to the snowy streets of New Hampshire, where she knocked on the doors of potential voters.

While de Blasio never got any face time with Clinton when he campaigned for her in Iowa, that was not the case for the speaker in the Granite State.

But that wasn't all. Mark-Viverito was off again shortly thereafter — this time to Miami and Orlando, Florida — canvassing salons and rallying Clinton volunteers and voters.

Closer to home, Mark-Viverito took Clinton on a tour of public housing.

All of this, has propelled the speaker onto the national stage. She has become a surrogate for Clinton to speak on issues close to women and Latinos.

"I am solidly behind Hillary Clinton," Mark-Viverito said. "She has been a friend to Puerto Rico. She is there today."

Last month, the speaker had a private meeting with the Chairwoman of the Democratic National Committee, Debbie Wasserman Schultz, to discuss Latino outreach.

We are told the speaker hopes to land a speaking spot at the Democratic National Convention later this summer. A spokesperson there tells us those speakers have not been selected just yet.

Regardless, all of this attention has fueled speculation that Mark-Viverito could be eyeing a job in a potential Clinton administration.

It's something she isn't ruling out.

"I always leave the doors open for any possibility," the speaker said.