They said the opportunity for the fresh start they were hoping for — after deposing a dictator last year and holding national elections — has been squandered.

The divisions were on display again last week as opposition leaders heckled and then walked out when Mr. Mnangagwa tried to deliver his first State of the Nation address, a speech ironically appealing for national unity and moving beyond the animosities dating back to the Robert Mugabe presidency.

“Most of us, the young people, are jobless, and there is nothing new that we can expect from the ZANU-PF,” said Sabina Ndlovu, 23 of Harare, referring to the ruling Zimbabwe African National Union-Patriotic Front party, which is still in power 38 years after the country won its independence from Britain. “Emmerson Mnangagwa had been Mugabe’s lieutenant all these years, and there is nothing we expect him to do to bring change in our lives.”

In November, Zimbabwe did the once unthinkable and deposed the frail 93-year-old Mr. Mugabe after 37 years in power. Hope surged in Zimbabwe and beyond that one of the world’s poorest and worst-governed countries had finally turned a corner.