A secretive Democratic super PAC has been quietly running a massive Spanish-language ad campaign in support of Vice President Kamala Harris, pumping tens of millions of dollars into trying to reach persuadable Latino voters.

Future Forward, a pro-Harris super PAC, keeps a low profile and rarely speaks publicly about the staggering $422 million it has spent so far in the 2024 campaign, but an adviser to the group shared some details about its efforts to reach Latinos with NBC News on condition of anonymity.

The group has already spent nearly $30 million on Spanish-language TV, radio and digital ads, according to the adviser, which would likely make it the largest Spanish-language ad campaign of this election (and potentially of all time if spending keeps pace through Election Day).

That’s an unusually large investment in Spanish-language media. By contrast, for instance, Republicans have touted $1 million and $5 million Spanish-language ad campaigns this election. 

With its Latino vote program overseen by veteran Democratic Latino strategists Cristobal Alex and Pili Tobar, Future Forward has run Spanish-language TV and radio ads in Arizona and Nevada as well as media markets in battleground states with large Latino populations, including Atlanta, Philadelphia, Milwaukee and Raleigh, North Carolina. Its digital ads have reached 4.5 million Latinos, according to the adviser.

The group believes voters who consume Spanish-language media are more likely to be persuadable in part because they have been exposed to fewer ads than voters who consume English-language media, which is saturated with political messaging in battlegrounds.

Future Forward is known for its rigorous testing of ads and the adviser said they tested at least 20 versions of each ad that ran with Spanish-speaking Latino voters before putting them on air.

“This Spanish-language ad campaign recognizes the crucial need to engage Latino voters in battleground states—ensuring their voices and perspectives are at the forefront of national policies that impact economic growth, affordability, and opportunities for all Americans,” Future Forward President Chauncey McLean said in a statement last month when it announced a round of ads last month with one of its partners, UnidosUS Action PAC.

It also ran Spanish-language ads with Somos PAC and others. 

While Democratic messaging aimed at Latino voters in the past has often focused on immigration or Trump’s disparaging comments about Hispanic migrants, Future Forwards’s Spanish-language ads tend to focus on the economy.

One radio ad, for instance, plays a clip of Trump saying he has “concepts of a plan” for health care reform before the narrator says that, after almost 10 years of seeking the presidency, “Trump no tiene un plan,” which translates to “Trump doesn’t have a plan.” The narrator goes on to say that “el plan de Kamala Harris’” is about creating a future that helps “la gente trabajadora” — working people — get ahead.

While Latino voters skew Democratic and have always been critical in certain states, they’ve become a more contested demographic between both parties as polls show Trump and other Republicans making inroads with Latinos, especially those without college degrees.

Both campaigns and allied outside groups are competing aggressively for Latino voters, not just in states like Arizona, but also places like Pennsylvania’s so-called “Latino Belt” around Bethlehem and Allentown, northwest of Philadelphia but within its media market.

Latinos communities are also rapidly growing in places like Atlanta and Milwaukee, changing how campaigns think about winning states like Georgia, Wisconsin and North Carolina,

A national NBC News/Telemundo/CNBC poll from last month found that Harris leads Trump 54-40% among Latinos. That’s a few percentage points shy of President Joe Biden’s performance with the group in 2020, according to Pew’s validated voter data from that election, and well below the massive 71- 27% margin former President Barack Obama enjoyed with Latinos over Mitt Romney in 2012.

A new survey from Equis Research, which specializes in Latino voter sentiment, showed that Harris has for the first time taken a slight lead among Latino voters on who is “better for the economy,” suggesting her message may be breaking through to some.