On the evening of Feb. 19, 650 residents of Rishon Lezion braved a storm of rain mixed with hail to attend a campaign event for Moshe Kahlon, chair of the Kulanu Party, at the Mofet Hall.

While Kahlon was laying out his vision before a packed house, his advisers were intently following media reports about the testimony against Prime Minister Benjamin Netanyahu and his wife being given at the same time to police by Manny Naftali, the former housekeeper of the prime minister’s official residence.

Naftali’s testimony is part of probably the most severe crisis of Netanyahu’s campaign and the embodiment of the prime minister’s worst nightmares. It was the exact moment at which Netanyahu lost control of the electoral agenda and his campaign, and perhaps even the premiership.

This is a dramatic development making Netanyahu increasingly vulnerable. It also positions Kahlon as the man who will determine whether Netanyahu will go on to another term as prime minister. The reason is simple: Without him, the center-left will be unable to put together a coalition government. He is the most essential component of the anti-Netanyahu bloc that Zionist Camp co-chair Isaac Herzog aspires to form after the election.