One month before Spain’s national elections on Nov. 29, Prime Minister Pedro Sánchez held a long meeting in Madrid’s Atocha station with officials from the train traffic control center that his government has blamed for a devastating crash that killed at least 69 people.

As his motorcade pulled away, Felis Caballero, a pharmaceutical company employee, rolled her luggage in front of the station.

“I travel a lot, and the train for me was always very safe, but not lately,” she said, adding that two mass-casualty accidents this year had eroded her faith in the rail system, and in Mr. Sánchez.

A self-described moderate from a town in central Spain near the site of the accident, Ms. Caballero, 60, said she wasn’t sure whether she would vote for the mainstream conservative opposition or cast a blank ballot. But one thing was clear, she said: It wouldn’t be for Mr. Sánchez’s Socialist Party. Under him, she said, things were “going badly.”

Mr. Sánchez, one of the longest-serving leaders in Europe, has faced his fair share of disasters during his eight years in power. Natural disasters have included the coronavirus outbreak, deadly floods in Valencia, wildfires and the eruption of a volcano in the Canary Islands.

He has governed through infrastructure nightmares, including a blackout across the country and a January train crash that killed 46 and was apparently caused by faulty rail on the track between Madrid and Seville. And just this summer, about 80,000 migrants breached Morocco’s border with the Spanish exclave of Ceuta in North Africa, though all but a few thousand soon returned to Morocco.