Former Senator Joe Manchin III of West Virginia said he told Senator Susan Collins, who is locked in a tough re-election fight, “Whenever you run again, I’m going to come.”

© Sarah Silbiger for The New York Times

High diesel costs have posed a problem for Republicans in the midterms, but President Trump’s decision did not satisfy some candidates in key Senate races.

© Emily Elconin for The New York Times; Doug Mills The New York Times

The president defended the complexes, which have become a liability for Senator Jon Husted in a challenging midterm race.

© Kenny Holston/The New York Times

It was the latest mixed messaging from President Trump, who regularly votes by mail, but has made baseless claims that the practice is “inherently corrupt.”

© Nick Hagen for The New York Times