This November, voters in rural Perry County, Mo., will face a ballot with candidates for a bevy of local offices: state senator, state representative and circuit judge; two county commissioners, sheriff and many more.

What they won’t face is a choice.

Each of the 17 down-ballot races in Perry County has only one candidate. Just south, Cape Girardeau County fares only slightly better: Three of 12 races have two candidates.

All the candidates in the uncontested races are Republicans. And in those few races where a Democrat also is on the ballot, Republican victories are foregone conclusions in a rural area where voters overwhelmingly favor the G.O.P.

“There’s strength in numbers,” Kelly McKerrow, the chairwoman of the Perry County Democratic Party organization, said. “And we just don’t have them.”

Amid the feverish handicapping of an election often called crucial to the future of American democracy, Missouri tells a different story, repeated time and again across a deeply polarized country where it can feel futile to run as a Democrat or Republican in a stronghold of the other party. In half of all races for partisan offices, candidates are elected — often multiple times — without opposition.