Manchester, New Hampshire — Bernie Sanders' campaign manager Faiz Shakir says victory in New Hampshire is "absolutely critical" to the campaign's efforts to capture the Democratic nomination, telling CBS News the campaign will be ramping up its presence in the Granite State in the coming months.

"I don't like the phraseology of 'must-win New Hampshire,' but it is critical," Shakir said. "And we are going to invest in this state and are investing in the state to do everything in our power to win it."

The campaign has been late in building out a ground organization in New Hampshire, lagging behind Senator Elizabeth Warren's operation. But in a wide-ranging interview here, Shakir said that has been by design, with the campaign planning "for the long haul."

Get updates from the campaign trail delivered to your inbox

"We could afford, over a period of time, to allow a lesser investment and then increase that investment over time," Shakir said. "So by the end of this, I promise you, if we aren't the candidate with the most staff and most volunteers, I will be stunned."

Sanders has spent eight days campaigning in New Hampshire, half as much time invested by Warren, who has spent 16 days in the state. But Shakir said Sanders is already familiar to primary voters here, having won the 2016 primary over Hillary Clinton by more than 20 points. Other candidates have had to spend time introducing themselves, Shakir said.

"And so they were here more. If you looked at some of our early visits, in March and April, we were in places like Michigan, Wisconsin, Pennsylvania," he said.

Senator Bernie Sanders greets supporters in the audience after addressing a rally during a campaign stop on Sunday, March 10, 2019, in Concord, New Hampshire. AP

Shakir said the campaign has instead focused on pitching an "electability message" in general election swing states. "In order to defeat Donald Trump, you have to carry those states. And he has a unique appeal in those states. We got criticized for it, but we did spend some time trying to make the case for electability."

"There'll be two questions that resolve this race," he said. "One, who is best to defeat Donald Trump? And two, who do you trust to make the change happen that you so desperately want? I think when people order those two questions, rank the candidates, we'll be fine."

The goal of the Sanders' campaign, Shakir said, is to find "unlikely" voters — Uber drivers, postal workers, employees of Walmart and McDonald's — and turn them into "likely" voters. "That is the thrust. That is the vision. That is the strategy," he said.

A Suffolk University/Boston Globe poll in early August of likely Democratic voters in New Hampshire found Joe Biden in the lead at 21%, followed by Sanders with 17% and Warren at 14%. About 20% of respondents said they were undecided.

But Shakir argued the voters the Sanders campaign is targeting are not represented in public polling data. "I don't think many of them would identify themselves as likely voters right now, and therefore wouldn't get through a voter screen on a poll right now — I mean, they wouldn't identify themselves as likely voters," he said.

Asked why Sanders has not targeted Warren, perhaps his chief progressive rival, Shakir laughed.

"Well, specifically about Elizabeth, I mean, they have been friends. And when I say friends, truly legitimate friends who like and respect each other," he said. "If he were not running for president or she were not running for president, I guarantee you they would be soliciting advice about how to win from each other."

Shakir, who played second base at Harvard, offered an analogy: "Your best friend is up to bat. I'm pitching. Do I want to hit them in the head with the pitch? No, I want to play my best. I want to perform. I don't want it to come at his or her cost. I want to win on my own merits."

The campaign manager did not hold back in his critique of cable news, repeating earlier criticisms of the media articulated on the stump time and time again by Sanders himself.

"We have more horse-racing, nonsense coverage because national media and Facebook is taking over," he said. "But I think that the data point that bothers me most, and I think bothers the senator most, is when you have a media that tends to look at everything in the left-right spectrum. You're not doing justice to him."

Shakir listed cable news networks, but stopped short of calling out specific journalists or commentators.

"Look at that roster of people. How many of them literally hate Bernie Sanders?" he asked. "How do you have so many people out there who believe in 'Medicare for All,' and yet, you go on the turn on the TV and you got a health care executive on? Oh, there's Goldman Sachs' CEO on there. Oh, there's some traditional Democratic pundit who hates Bernie Sanders on there, talking about health care, who thinks Medicare for All is a terrible idea and will be terrible for the Democratic Party."

Asked if he felt this narrative of unfair media treatment in some way helped the senator, Shakir shook his head.

"This isn't the game though, right? I think that often gets lost in some of the media coverage. Like, 'Oh, it was really smart of Bernie Sanders pick a fight with the media because that worked for Donald Trump.' Nonsense!"

He continued: "I mean, we did an analysis of The Washington Post and how they cover labor. You don't have labor reporters. You know, he rolls out things that affect labor and it's always covered through the lens of the horse race. 'How will this affect you politically?' I'm like, how about, how will it affect people? How will it affect actual people's lives? Can we write a story about that before we jump there?"

The first Muslim presidential campaign manager, Shakir cited his interactions with voters in mosques around the country as evidence of the potential to expand the primary electorate.

"I traverse this place as the first Muslim campaign manager," Shakir said. "There are oftentimes pockets of Muslims. I go to some mosques I see. I ask, 'Have you voted before?' They say, 'No, I have voted before.' I say, 'Are you thinking about voting?' 'Yes, I'm thinking about voting.' And so then I ask them, 'When are you going to vote?' They say, 'In November of 2020.' I'm like, 'Nope, too late. You missed the most important vote. You gotta vote in the primary.'"

Speaking about the current president, Shakir said, "One of the reasons he won was because he campaigned as a fake Bernie Sanders. He said, 'I'm going to drain the swamp. I'm going to go cut fair trade deals. I'm going to take on Goldman Sachs. I'm going to be a champion for the working class.'"

Shakir paused.

"America, he's a liar. He's a pathological liar. He betrayed you all. And in order to defeat him, I believe you need credibility. You have to be real. Bernie Sanders is in the best position to do that."