Nieves was skeptical of parahumans and viewed them negatively, as "wolves" that unpowered humans were trapped with. He opposed having parahumans in any position of power over unpowered humans. He also advocated for an organized resettlement of Earth Bet as a major part of his political platform.  Nieves had an extreme distaste for authority figures who were not capable of competent leadership.
Nieves participated in several informal meetings with the other mayoral candidates, including Jeanne Wynn and Sierra Kiley. At one meeting, he met with the representatives from Earth Cheit, where he was skeptical of Cheit's arrangement to supply Earth Gimel in exchange for "goodwill". After quitting the mayoral race, he was still willing to work with Mortari and with John Druck's organized labor in order to maintain the portal network.
As a mayoral candidate, Nieves participated in the informal governance of The City, attending meetings three to five days a week.. He eventually withdrew from the meetings, and from the mayoral race, rather than work with Jeanne Wynn.
After withdrawing from the mayoral race, he concentrated on staffing the Earth Bet portal with his followers, totaling twenty to thirty percent of the workforce there. He still intended to try recolonizing Earth Bet.
Nieves was present when the Gimel-Bet portal was attacked by unknown militants, which killed many of the workers and refugees.. After Dragon and Defiant thwarted the attack, he criticized both them and the Shepherds for their handling of the situation.
A few days after the attack, Nieves was approached by Erwin Daeyoung, who offered him evidence that his fellow mayoral candidates Jeanne Wynn and Sierra Kiley were both associates of Tattletale. Daeyoung attempted to recruit him on behalf of an unknown faction, proposing that Gimel.US should become a client state rather than being ruled by parahuman criminals. The result of this recruitment attempt remains to be seen.
He continued collecting evidence, and eventually outed mayor Wynn as parahuman to the public, as well as provided some evidence of parahuman nature of Shin and Cheit rulers.
Following the Teacher's defeat by The Wardens, terror-attack on mayor Wynn and call to evacuate The City, Nieves brought Dinah to Wardens. During the meeting it was revealed that he lost control over anti-parahuman faction.
↑Mr. Nieves, another prospective mayor, though he didn’t have the footing the others did, his chances were better than Ms. Kiley’s. - Interlude 2 II
↑Nieves didn’t sound casual. “It’s one more thing. Ninety-nine times out of a hundred, it’s the parahumans. It’s wolves people like me are trapped in a cage with, and they’re gathering into packs and reverting to their feral programming.” - Interlude; Citrine
↑“These wolves killed billions,” Gary Nieves said. “I don’t think we can afford to give them more power over us. We don’t have that much left to spare.” - Interlude; Citrine
↑“I serve a dwindling base. Every day that passes that we don’t go back to Bet to rebuild is a day I lose the faith of my supporters.” - Interlude; Citrine
↑When he’d been in fourth grade, an abysmal teacher had left him so stressed out that he’d gotten an ulcer. It was the kind of person he was. He could remember the ambient pain across his stomach, the distended way he’d felt, as if the stress had gathered inside him and was stretching his skin, and he could remember the acid taste in his mouth. That teacher and that experience had shaped him, driving home a distaste for authority figures who couldn’t lead. - Interlude; Gary
↑“They’ve been giving us supply for nothing?” Nieves asked, raising his voice. “You idiots. You’ve profited off of their so-called generosity, but you’ve been selling us out.” - Flare Interlude 2
↑The ‘heroes’ did their own thing. Other factions were serving their own leaders. Druck’s labor, Mortari reporting to Wynn. That left a share of maybe twenty or thirty percent who were citizen volunteers, serving under him. - Interlude; Gary
↑Gary Nieves was a little on the portly side, and if he wasn’t at least forty, he certainly looked it. Otherwise, the man looked after himself and portrayed a good face to his constituency. - Interlude; Citrine
↑“I’m done,” Mr. Nieves said. “You don’t need to worry about me anymore. I’m not a general who can handle this war that seems so inevitable, and I’m not someone who can come up with computer programs that break something this chaotic into something deceptively elegant-” Interlude; Citrine
↑ Twenty to thirty percent of the people at this station were people he’d recruited or people who worked alongside him. Ostensibly, they were largely in support of recolonizing Earth B. - Interlude; Gary
↑Things were still creeping forward when a sharp sound cracked through the air. His first instinct was to think it was something like the truck jackknifing. A mechanical failure, a backfire-
He heard the screams. The parahuman that had been perched atop a truck hit the ground, luminescent purple blood splattering to the ground around him. - Interlude; Gary
↑“It’s not where we are overall, but it’s where we were that moment. You want to open a dialogue, but- you weren’t here. The Shepherds weren’t here. In my limited interactions with parahumans, I keep on noticing- over and over again, even the good ones, we’ll hear you say that you forget our names, or we all sort of ‘blend into each other’. Again and again. There’s a disconnect, where we don’t even rate.” - Interlude; Gary
↑Gary looked. It was Sierra Kiley, one of the other past contenders for the mayorship. She too had stepped down. In the picture, she stood talking with the leader of the Undersiders and Citrine- Jeanne Wynn.
↑“Think, Gary. What do these other Earths want? Why do they threaten war and pick at our weaknesses with increasing viciousness? They want the territory. A world of resources, and a network of portals.”
“We give it to them. We promise leadership without parahumans in charge, stacking the deck. We turn to an established government we’re on friendly terms with and we invite them in. We become a vassal state.”
“Who are you thinking of?” Gary asked.
“Nobody. That would be a decision for you to make without my input. If I told you one or the other, you would think I’m working on their behalf. There are options. It’s an idea that takes some getting used to, but if you’re thinking you’d like to go home… perhaps a middle-ground solution would be to open communications and borders with a world that has hints of our old amenities and culture.” - Interlude; Gary