For many members exhausted by years of seemingly intractable poverty, Mr. Deschene seemed to offer a way forward.

Then, days before the election, Mr. Deschene was disqualified, after a lawsuit called his Diné fluency into question. The disqualification unleashed a tit-for-tat legal battle that consumed the three branches of the tribal government, with the Legislature eventually voting to nullify the primary and start over.

Navajo voters began to tire of the soap opera. “It’s a mess,” Mr. Shirley said in a telephone interview. He did not attend the inauguration.

The nullification was quickly challenged in tribal court, and it remains unclear when an election will be held, who will run, and whether the fluency requirement will remain. The absence of a new president leaves in place Mr. Shelly, 67, who was faulted by voters for, among other things, attending a Washington Redskins game, where he sat alongside the team’s owner, Dan Snyder. (Many Native Americans consider the team’s name offensive.)

Image The Legislature voted to nullify the results of the 2014 presidential race because of disagreements. Credit... Monica Almeida/The New York Times

The Navajo Nation, comprising some 300,000 members, has the largest reservation in the United States, a vast region of towering red rocks and scrubby yellow plains that is roughly the size of West Virginia. It is run by a three-branch government that is comparable to a state body, with notable exceptions: The tribe does not have a constitution and is instead guided by a set of codes and a document outlining traditional values.

Central government is not a Navajo concept, but was instead imposed on the tribe by the federal government in the 1920s. While the tribe has had some form of central governing body since 1922, the existing system was put in place in 1990, after a corruption scandal led to deadly riots and then democratic reforms. Today, the president manages most of a $500 million budget and acts as a diplomat to states, other tribes and the federal government, serving a term of four years.