Even as he accused Mr. Mugabe of flouting provisions of the so-called unity government, many critics said Mr. Tsvangirai had been outwitted and co-opted by the president, his former sworn enemy. Indeed, Mr. Tsvangirai seemed to settle into a more comfortable relationship with him, built on the privileges of office.

In 2012, after Mr. Tsvangirai celebrated his second marriage with a glitzy party attended by guests arriving in Bentleys, Mercedes and BMWs, some of his followers were aghast at the ostentatiousness of the display and questioned who had paid for it.

By the time elections were held the following year, Mr. Tsvangirai was greatly weakened. He accused Mr. Mugabe of rigging the election and challenged him in the courts. But Mr. Mugabe claimed victory with 61 percent of the vote, compared with 34 percent for Mr. Tsvangirai, and it seemed that Mr. Tsvangirai’s brush with high office was over. That was certainly Mr. Mugabe’s view.

“We have thrown the enemy away like garbage,” Mr. Mugabe said. “We say to them: You are never going to rise again.”

For all that, Mr. Tsvangirai appeared in recent months to be attempting a comeback, even as he made frequent trips abroad for colon cancer treatment.