The latest electricity crisis, which has plunged the country into rolling blackouts just days before elections, could alter the outcome of Monday’s municipal polls, which were already set to be a watershed moment for SA’s two biggest political parties.

The power crisis, which has led SA to suffer its worst cuts since load-shedding made it into the country’s vocabulary about 14 years ago, has cast a shadow over the ANC’s campaign, with the party already on the defensive about a lack of delivery and collapsing municipalities...