Running the Democratic Republic of Congo is a tough and dangerous job. For decades, this African country – the size of Western Europe – has lurched between dictatorships, wars, and vast humanitarian crises. Despite extraordinary natural resources, it remains desperately poor. Two leaders have been killed. And yet, 19 candidates are in the race to become Congo’s next president in elections, the fourth in Congo’s history, that took place on Wednesday — and another 100,000 are running for seats in national, regional and local assemblies. The vote is being closely watched not only by Congo’s nine neighbors, with whom it shares 6,500 miles of borders, but also by foreign powers. International interest in Congo has soared in recent years as countries try to stem climate change and transition to clean energy: Congo has the world’s second-largest rainforest, as well as deep stores of the rare minerals needed to make electric cars and solar panels. After polling stations opened — or failed to open — creating long lines and scenes of disorder, the election took a rocky turn. In the capital, Kinshasa, where polling stations opened hours late, heated confrontations ensued between voters and officials. In several provincial towns, frustrated voters ransacked polling sites. By midmorning, the largest poll monitoring body, run by the Roman Catholic Church, had reported violence at 8 percent of polling stations. By Wednesday evening, the national election commission announced that voting would continue on Thursday in areas where polling stations had failed to open at all. The most famous presidential candidate is Denis Mukwege, a gynecologist who won the Nobel Peace Prize in 2018 for his work with sexual assault victims. But the firm favorite is the incumbent, President Felix Tshisekedi. A voter poll published Tuesday by Ebuteli, a Congolese political research organization, and the Congo Research Group, based at New York University, gave Mr. Tshisekedi 49 percent support. His nearest rival, Moïse Katumbi, a business tycoon and one-time governor of the mineral-rich Katanga province, got 28 percent. Mr. Mukwege got less than 1 percent. Populism and mudslinging dominated the monthlong campaign. Candidates stoked ethnic tensions with inflammatory language, or even threatened to declare war on neighboring countries. At least one person died in clashes between rival groups, Human Rights Watch said. Yet many Congolese have been eager to vote. A frantic cacophony filled the broken streets of Kinshasa this week as rival campaigns made a last-minute push for votes. Music blared. Lines of motorbikes splashed through puddles. Bombast flowed, as did money. “We are the victory before the victory,” declared Rovernick Kola, 29, a motorbike rider waiting to be paid $20 for driving in a convoy that waved posters of a parliamentary candidate.