The contender

If Democrats are going to hold on to the Senate, they are going to need at least one major longshot to come through. At this point, Dan Osborn has a better shot than Jon Tester:

The populist appeal — in which members of both major political parties are cast as feline villains and Mr. Osborn as one of the preyed-upon rodents — has helped propel his challenge to Senator Deb Fischer, a second-term Republican who until recently had appeared to be on a glide path to re-election. Now, polls show the two in a tightening race that could potentially sway the balance of power in the Senate.

Over the past two decades, Republicans have consolidated a near monopoly in the Great Plains, a shift across a stretch of prairie once dominated by Democrats that could become complete in November if Senator Jon Tester of Montana loses his seat.

But this year, Nebraska has thrown Republicans for a loop. Mr. Osborn’s dark-horse, grass-roots campaign has transformed what was expected to be a sleepy race into a late-breaking and high-stakes clash that has forced Ms. Fischer and her allies to invest millions of dollars to avoid an upset.

If you’re consumed by anxiety about the election and want to do something other than sharing your feelings on social media, helping out Osborn — who doesn’t have access to party funds and is going to face a McConnell ad blitz in the last 10 days — is probably the single most consequential thing you can do.