NAIROBI, Kenya — It was always about more than a single election.

Kenya’s judiciary, which has battled for years to establish its independence, asserted itself last month with a decision that surprised the world, nullifying a tainted presidential election and demanding a repeat to prevent fraud.

It was a moment of democratic triumph, of an independent court defending a young constitution — or at least it seemed like that, until the last minute.

This week, for the second time, Kenyan activists and lawyers pinned their hopes on the Supreme Court, which agreed to hear a petition on the credibility of the new election. Chief Justice David Maraga issued an order requiring all judges to work on Wednesday, despite a hastily declared public holiday, and he promised a 10 a.m. hearing that might make or break the next day’s poll.

But when the time came, only one of the other six judges showed up. Mr. Maraga, sitting alone on the bench, announced that, lacking a quorum, the hearing couldn’t happen.