Nithya Raman’s entry tests Karen Bass from the left in Los Angeles mayoral race

Los Angeles City Councilmember Nithya Raman’s late entry into the mayoral race has upended what had been shaping up as a more conventional reelection contest for Mayor Karen Bass, injecting a progressive challenge that political analysts say could fundamentally alter the dynamics of the June primary — and make a runoff far more likely.

Political strategists and observers say Raman’s decision to run, made just hours before the filing deadline Saturday, presents a fundamentally different...