Marin is calling on the federal government to address its significant undercount of people of color in the 2020 census. Last month, the Board of Supervisors sent a letter to the Census Bureau asking it to rectify the resulting data, which the agency admitted missed roughly 5 percent of Latinos, along with 5.6 percent of Native Americans and 3.3 percent of African Americans. “We urge that revisions be instituted to prevent future undercounts and to address the damage done by the 2020 census,” Supervisor Katie Rice wrote in the letter. Census data shows West Marin is about 13 percent Latino but, like many rural areas, it has had a relatively low response rate. Although more than three quarters of Marin residents responded to the 2020 census, a much higher rate than California as a whole, the suburban-rural divide was stark. In Point Reyes Station, Inverness, Nicasio, Tomales and the Point Reyes National Seashore, only about 43 percent of residents responded. An even lower number, just 37 percent, of Bolinas and Stinson Beach residents answered. Demographers have other methods of counting those who don’t respond, including knocking on doors and asking neighbors, but areas with low self-response rates are more likely to end up undercounted. The Census Bureau weighs the accuracy of its own final count against the true national population by using follow-up surveys and broad demographic analyses of birth and death records, immigration estimates and Medicare records. There’s no local data on the extent of the undercount, but community leaders are concerned that West Marin’s count could be just as inaccurate as the national estimate, or worse. During the census, West Marin Community Services staff canvassed on the phone, sent thousands of informational cards to post office boxes and used gift cards to incentivize families to take the census on a laptop at the food pantry. But the nonprofit’s executive director, Socorro Romo, believes the census missed many of West Marin’s Latinos. She said widespread fears stemming from former president Donald Trump’s anti-immigrant rhetoric and the threat of a citizenship question dampened participation that was already challenged. “The propaganda from the previous administration had a huge impact on how the Latino community responded,” Ms. Romo said. “We did what we could, but I don’t think we were very effective because every effort we made was jeopardized by the [Trump] administration.” There were several other reasons for the undercount. Many Latinos in West Marin live on ranches or dairies that are home to multiple other families but receive just one census form. The Census Bureau doesn’t send forms to P.O. boxes, where most West Marin residents get their mail, because the data is tied to physical residences. The effects of an undercount could be painful over the next decade. About 35 percent of the county’s budget comes from the federal and state governments, which use local census data when deciding how much to allocate. An often-cited estimate is that one person counted in the census represents about $10,000 in funding for the county over 10 years. “For every person that we undercount, there’s less money coming our way,” county budget manager Bret Uppendahl said. “It makes us less competitive across the board.” Affordable housing, mental health services and bilingual programs are among the county expenditures that could see lower federal or state funding than necessary because of the undercount. “The populations that have historically been undercounted are the ones that need more support and help from the county government,” Mr. Uppendahl said.