Turnout for Tuesday’s mayoral primary in the District was the worst the city has seen in at least three decades, revealing a broad public apathy toward the District’s political life in a period of both economic dynamism and scandal.

After years spent rehashing the District’s 2010 mayor’s race — and three resignations from the D.C. Council on corruption or fraud charges — voters thwarted Mayor Vincent C. Gray’s reelection bid, selecting Muriel Bowser as the Democratic nominee. Voters also offered a broader verdict by abandoning the electoral process in massive numbers.

Only about a quarter of the nearly 370,000 people eligible to cast ballots in Tuesday’s contest did so. The percentage of voters coming out for mayoral primaries has never dipped below 32 percent in more than 30 years, according to the District’s Board of Elections.

The District’s turnout rate Tuesday lagged that of a high-profile mayor’s race in Chicago featuring Rahm Emanuel, where turnout was 42 percent, according to elections officials there. But it was on par with the recent Democratic primary in New York, in which voters selected Bill de Blasio in a contest that had voter turnout of 23 percent.

Tens of thousands of voters — most of them Gray supporters four years ago — stayed home this time. Turnout was so low that Bowser netted fewer votes in victory than her former patron, then-Mayor Adrian M. Fenty, received in 2010 when he lost to Gray, according to the Board of Election’s latest tally.

Speaking at the National Press Club on Wednesday, Democratic D.C. mayoral nominee Muriel Bowser says she still has not spoken with Mayor Vincent Gray after Tuesday's primary win. (Pamela Kirkland and Randolph Smith/The Washington Post)

Turnout in that 2010 election was 37 percent, compared with the board’s most recent count of 23 percent, according to city election officials, who said they expected a much better showing.

“It was definitely much lower than we had anticipated,” said Tamara Robinson, a spokeswoman for the Board of Elections. “We had been hoping for 40 percent turnout, and we got little over half of that.”

Robinson cited everything from the weather — including snow during early voting and soggy conditions this past weekend during voter mobilization efforts — to the wide selection of mayoral candidates on the ballot as possible reasons for the weak turnout. “When you have such a large field of candidates, it makes it harder for voters to decide,” Robinson said. “Some people, for whatever reason, might have decided to sit this one out.”

Robinson also said that thousands of absentee and provisional ballots remain to be counted and are not yet reflected in the board’s most recent, unofficial voting results. There were 5,319 absentee ballots requested, and approximately 10,000 provisional ballots are outstanding, Robinson said. Among the provisional ballots were those submitted by people at incorrect precincts as well as some from voters with no party affiliation who were not allowed to take part and whose ballots will be rejected, she said.

Even if all the outstanding potential votes were added to the current tally, Tuesday’s turnout total would rise from 23 percent to just 27 percent.

An analysis of the Board of Election’s latest count offers a view into just how far voter participation in the District dropped.

About 52,000 fewer Democratic voters cast ballots in Tuesday’s mayoral primary than did in 2010, and Gray received about 46,000 fewer votes than he did last time. Even in the three wards Gray won, the number of votes dropped by about 26,000.

Working with D.C. Council member Marion Barry (D-Ward 8), Gray made the strategic decision to conclude his campaign with a strong push for African American voters east of the Anacostia River, in wards 7 and 8. But the effort fell short. Gray’s winning margin in predominantly black precincts citywide dropped from 34,500 to 5,100.

Another key difference from 2010: The percentage of voters who cast ballots for those other than the two leading candidates increased sharply. Among them this year were council members Tommy Wells, Jack Evans and Vincent B. Orange as well as restaurateur Andy Shallal.

Michael P. McDonald, an associate professor of government and politics at George Mason University, said there are numerous reasons would-be voters stay away.

“Part of it is interest, and part of it’s awareness,” McDonald said. Some communities he has examined have had turnout in the teens or single digits. The District’s turnout rate in the 20s is “actually pretty good in comparison to other places in the country,” he added.