(CNN) Millions of workers aren't getting any help from the largest emergency aid deal in US history .

When stimulus checks start going out across the country, undocumented immigrants won't be receiving them.

That's not a surprise. They aren't eligible for most federal benefits

Critics counter that it's not the US government's place to bankroll someone who broke the law, and that as unemployment skyrockets , American workers should come first.

This isn't just another set of salvos in the political battle over immigration that's raged in our country for decades. It's a very different debate -- because of who could be impacted, and what's at stake.

Even though Congress has cast its votes on the stimulus bill, the debate is far from over, and the impact of what's happened so far is only just coming to light. Here's a look at why this issue matters, and what could happen next.

The argument: 'Everyone has an immigrant neighbor'

Unauthorized workers make up about 5% of the US labor force -- around 7.6 million people, according to the latest estimates from the Pew Research Center.

Advocates argue the coronavirus crisis that's devastated global markets, overwhelmed hospitals and left millions without jobs is having an outsized impact on undocumented workers. Many had service-sector jobs that were decimated by the pandemic. Those who remain employed largely don't have the option of working from home , and are risking their safety to keep supply chains going.

"It's undocumented workers that are still in the fields, still in the factories, still the janitors in the buildings, still looking for work as day laborers," says S.G. Sarmiento, campaign director for the National Day Laborer Organizing Network.

At first glance, you wouldn't necessarily expect this group to be included in the stimulus deal. After all, they generally aren't eligible for government benefits. And these days it's rare to see leaders in Washington rolling out the welcome mat for immigrants.

But because of the threat the novel coronavirus poses, advocates argue this shouldn't be treated as business as usual. In a public health crisis, they say, if someone feels like they can't miss work or can't afford medical care, that impacts the entire community.

"From a public health perspective, you cannot have an effective national response to a pandemic that excludes enormous segments of the population. That's both illogical and immoral," Sarmiento says.

Stimulus checks aren't the only option on the table. Another thing advocates have been pushing for that wasn't included in the deal lawmakers approved: more access to testing and emergency medical care for immigrants in the Deferred Action for Childhood Arrivals and Temporary Protected Status programs.

"The package does not provide enough access to testing and treatment. ... We just think this is totally irresponsible and dangerous and infuriating," said Tyler Moran, executive director of the Immigration Hub, an immigrant advocacy organization. "Everyone's health literally depends on the health of your neighbor. And guess what? Everyone has an immigrant neighbor."

The counterargument: 'Our top priority has to be helping Americans'

Organizations that favor restricting immigration say that now, more than ever, it's clear that undocumented immigrants shouldn't be included in the stimulus package.

"With one of the worst jobless reports in quite a few years, the primary focus right now should be on American workers and lawful immigrants," said Chris Chmielenski, deputy director of Numbers USA. "We should make sure that those people are taken care of first."

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What about concerns that leaving undocumented immigrants out of the stimulus will have a detrimental impact on public health?

Chmielenski says the aid package includes funding for medical care providers who will test and treat patients regardless of immigration status.

"Our top priority has to be helping Americans and helping legal permanent residents who are most affected by the crisis both from a health perspective and economic perspective," he says.

One worker's perspective: 'The government is making us invisible'

Ingrid Vaca says this is her third week without work, and there's no end in sight.

"It's extremely difficult right now. I don't know what I'm going to do. ... I know I'm not going to have enough to pay my rent," the 57-year-old Virginia housekeeper says.

"The government is making us invisible. The fact that I'm a person without documents in this country does not mean that I'm not a human being, that I'm not hungry," she says. "The government uses us when it needs us. ... We keep their houses clean, we take care of their children and their elders. And we do it with a lot of love."

"We're just asking for a little grain of sand in return," she says.

The next steps: 'We have to stick together'

Jesus Lopez burned through his savings when his truck broke down last month.

Now construction projects he'd counted on have been called off.

The 49-year-old day laborer in Southern California has seen this happen before. Work also ground to a halt after the terrorist attacks on September 11, 2001. But Lopez says this time is different.

"This virus is invisible," he says, "and we're at risk. It's a ghost behind us."

Mexican migrant workers harvest organic parsley at a Colorado farm in 2011.

Even so, Lopez says he can't afford not to work. This week he helped do some repairs at a restaurant and went to Home Depot to get materials.

"I have to take the risk," he says. "I had to go wearing gloves, a mask, glasses."

Groups that advocate for immigrant workers say stories like this are playing out across the country. Many are raising money for emergency funds to help those with no safety net.

"This is a crisis moment for hundreds of thousands of undocumented workers and families that don't have any sort of a basic work protections, like sick leave, like unemployment insurance," says Sarmiento of the National Day Laborer Organizing Network.

Lopez says he has enough money for two or three more days. After that, he's not sure what the future holds. But he knows he won't be getting any money from the government to help. Instead, he'll be turning to his friends and adapting however he can.

"That's what we do. ... We have to stick together," he says. "We have to turn to each other."