Known coronavirus cases in the United States have now exceeded 12 million, and the daily routines of large numbers of Americans are now shaped by their zip codes, governors, and beliefs about the virus. Do they wear masks? Go to school in person or online? To eat out? Be exposed to the virus?

The pandemic and the nation’s incoherent response have taken the notion of two Americas to a new extreme. The contrasts are particularly noticeable in South Dakota and New Mexico, states that live two different economies: one wide open, the other closed.

In South Dakota, where a conservative borderline philosophy dominates, the economy developed relatively well at 3.6 percent, which is well below the national average of 6.9 percent. Some cities, businesses, and school districts require masks or social distancing, but overall, the state has the fewest restrictions, neither a mask mandate nor significant restrictions on businesses.

However, hospitalization rates were the highest in the nation, and more than 7 percent of the population tested positive. The state has the second highest rate of new cases in the country.

Governor Kristi Noem, a Republican, sees her approach as a sign of freedom and criticizes restrictions as ineffective and economically destructive.

“You wouldn’t even know there was a pandemic,” said Heidi Haugan, mother of four young children in Sioux Falls, South Dakota’s largest city.

New Mexico has fewer cases per capita, but a more alarming trendline. The daily number of cases has more than doubled in the past two weeks. On Monday, Democratic Governor Michelle Lujan Grisham placed the state’s two million residents under the toughest restrictions in the country. It issued a two-week stay-at-home order, banning restaurant dining, and placing capacity limits on grocery stores and closing shopping malls, cinemas and gyms.

And the virus hit the economy. Unemployment in New Mexico has risen to 8 percent – roughly the same as in neighboring Republican-run Arizona – and small business owners have widespread concerns about the shutdown.

In both South Dakota and New Mexico, people suffer in a similar way – they suffer not only from economic and health problems, but also with family members and friends about the virus and how to fight it.

Allison Byington, who lives in South Dakota, said her mother recently referred to her as a murderer for refusing to wear a face mask. “We are no longer in a relationship,” said Ms. Byington.