The 2020 carnage for Iowa Democrats was wide and deep. The party lost a Senate race, gave up two congressional seats and lost half a dozen seats in the state legislature. Unified Republican rule in state government has led Gov. Kim Reynolds to sign permissive gun laws and new restrictions on voting this year, and lawmakers are moving to add a constitutional ban on abortion.

Many Democrats now believe that Iowa is all but lost to the party, and that it is time to let go, a view driving a fierce debate over whether to drop the state’s presidential caucuses from their leadoff role in 2024 and beyond. Iowa is small and unrepresentative, more than 90 percent white, and the 2020 election showed that Democrats’ future is in the Sun Belt, with its racially diverse electorate and college-educated suburbanites.

Other party strategists are quick to note that Mr. Biden barely won his two Sun Belt pickup states last year, Georgia and Arizona, and that the party can’t afford to bleed more of its traditional voters while making only tenuous inroads with a new constituency.

What’s the matter with Iowa, and by extension much of the northern Midwest, for Democrats? Many officials say the party’s cataclysmic losses stem from the erosion in quality of life in rural places like Des Moines County and small cities like Burlington, which are a microcosm for a hollowing out that has led to sweeping political realignments in parts of Iowa, Illinois, Wisconsin, Ohio and Pennsylvania.

Schools have closed, rural hospitals are cutting all but bare-bones care, and young people with college degrees have fled for opportunities in Des Moines or Chicago. Employers have backfilled jobs with immigrants, often after weakening unions and cutting pay.

“There’s just a discontent, an unhappiness here seeing communities shrink,” said Patty Judge, a Democrat and former lieutenant governor of Iowa. “That makes people very vulnerable to a quick fix. Donald Trump offered that: ‘Let’s make America great again, you’ve lost your voice, let’s have a voice again.’ People have bought into that.”