A supporter of Brazil’s far-right president Jair Bolsonaro has stabbed to death a backer of leftist former president Luiz Inácio Lula da Silva, in the latest instance of rising political tensions in the buildup to this year’s election.
The violence happened in the west-central state of Mato Grosso, after tempers frayed during an argument over support for the two candidates. Bolsonaro trails Lula in the polls in an election riven by…