President Biden, his wife Jill, and members of his administration are hitting the road, trying to persuade more Americans to get vaccinated against the coronavirus.

That effort is needed: Less than two-thirds of Americans age 12 and older have received a dose of the available vaccines, and only a little more than half are fully vaccinated. Yet vaccinations have tapered off significantly over the last two months, despite ample supplies of vaccine at zero price to recipients. It will take a major push for the United States to reach the 70% vaccination rate that hopefully will yield “herd immunity” and starve out the virus variants that are now circulating–including the new Delta variant that seems especially dangerous and could spread through the country like wildfire this fall.

Question is, will the Biden administration vaccination push do much good? Vaccination rates are tied to people’s politics, as those living in “red” states (that is, states that went to Donald Trump in the 2020 election) are less likely to get vaccinated than people in “blue” states. It’s doubtful that red-staters will become inclined to roll up their sleeves if (as the New York Times colorfully put it) Dr. Anthony Fauci, Biden’s high-profile adviser on the virus, knocked on their door.

Fauci recently focused on a more promising audience, “a predominately African American neighborhood in Washington,” according to the NYT. That makes sense; along with Trump voters, one of the most noteworthy groups with low vaccination rates is African Americans.

Still, what of red-staters? Their low vaccination rates allow the coronavirus to continue circulating and spawn variants, which will extend the pandemic in red and blue America alike. What the Biden administration needs is some “red team” champions to advocate vaccination among Trump voters.

This type of strategy was shown to work last year by Dr. Deborah Birx, who led the Trump administration’s coronavirus response. In the cover story for the new issue of Regulation, Kenyon College economist David Harrington demonstrates that facemask wearing increased in red states following visits by Birx, who spent much of the year hopscotching across the country encouraging people to take steps to avoid the virus. (Her efforts did not increase mask-wearing in blue states, but they were already wearing masks at a higher rate than red states.) Harrington estimates that in four states alone, her messaging helped save tens of thousands of lives.

His findings are especially provocative because Birx has been chastised for remaining in the administration instead of publicly breaking with Trump over his handling of the pandemic. Because she stayed with Trump, she was positioned to promote virus mitigation measures to people who especially needed to hear that message.

Those people need a similar message today about COVID vaccination. Hopefully, the Biden administration will not ignore that need, and find some red-team champions to deliver it.