Elsewhere, communities have been retrofitted to adapt to its senior population, with modifications to parks, new walking paths and bus services to ensure accessibility. The Iowa Democratic Party’s 99 new satellite caucuses, created to make the process more accessible, includes more than two dozen assisted-living facilities or sites frequented by seniors.

“It’s a hugely important constituency,” said Bill Schickel, mayor of Mason City, which still broadcasts its City Council meetings on a public access channel to serve its large senior population accustomed to watching meetings on television rather than streaming on the internet. “They have high voting numbers and are regular voters.”

Seniors’ concerns have dominated numerous campaign events in the state, so much so that younger voters have struggled for attention to their issues.

“O.K., so hi, I’m a student here,’’ said a young woman at Mr. Buttigieg’s town hall, which was at Dubuque University. “And I’ve been to a couple town halls: Booker, Warren, Biden. And at every single one I was probably one of three or four college students.” With so few of her peers in the crowd, she wanted to know: “How important is this generation in this election?”

Broadly, the economic discussion on the 2020 trail has incorporated issues of general concern to younger voters: student debt and free college; a general progressive pitch for wealth tax.

In Iowa earlier this month, though, one of the most intense battles between the leading candidates centered on a matter of great importance to older Iowans: Social Security.

Senator Bernie Sanders, 78, and former Vice President Joseph R. Biden Jr., 77, clashed repeatedly over the issue, as Mr. Sanders’s camp questioned Mr. Biden’s record on Social Security, seeking to cut into Mr. Biden’s appeal with older voters, while Mr. Biden insisted that he wanted to strengthen the program and expand benefits.