New Delhi, Oct. 7 -- Nearly every poster, stump speech or televised debate seems to reference the attack, which has scarred the country and remains fresh in the minds of voters. Three years on, the worst security failure in Israel's history now threatens to end the career of its longest-serving prime minister.

"October 7 is kind of a framework for the entire political discussion that is going on," said Tamar Hermann, an expert on Israeli public opinion at the Israel Democracy Institute, a Jerusalem think tank. "All of us are post-traumatic in a way."

Netanyahu's opponents want him to pay for the failures that led to the deadliest day in Israel's 78-year history and plunged the country into a series of inconclusive wars. His defenders sa...