From the article …

On March 23rd, as Mr Imamoglu was being moved to a maximum-security prison on the city’s outskirts, the opposition Republican People’s Party (CHP) staged a primary election to confirm him as its candidate in the next presidential elections, scheduled for 2028. It was open to all voters, not just CHP members. The party said 15m Turks took part.

… and …

Meral, a housewife, joined the protests with her daughter, a university student. “This is not about Imamoglu or the CHP,” she says. “This is because our right to vote and to be elected is being taken away.”