There are plenty of local reasons for the mayor's loss, not the least of which is the perception that he was aloof and inaccessible.
But there are national implications to the development. In the process of voting against Fenty, Washington voters may also drive off his divisive schools chancellor Michelle Rhee, a national face for public education reform who is closely tied to the Obama administration, which has actively sought to tie federal money to school performance.
Rhee won plaudits for upending the troubled school system and improving test scores. She was on the cover of Time, and is prominently featured in a new documentary, "Waiting for 'Superman.'"
But she made enemies too. She fired underperforming teachers, which mobilized the teachers' union against her. She closed some schools, which angered parents, particularly in the African American-dominated parts of the city. Rhee's emphasis on test scores as the benchmark for reform is also political.
Rhee and D.C. teachers agreed on a contract earlier this year after long and tense negotiations. But the animosity reappeared when Rhee fired more than 200 underperforming teachers less than two months before the primary.
The victor in Tuesday's Democratic primary – and therefore almost a sure winner come November in the overwhelmingly Democratic city – is D.C. City Council Chair Vincent Gray, a chief antagonist of Rhee at oversight hearings.
Gray has not said he would fire Rhee, but he hasn't said he would keep her on either.
"I have said on many occasions that after this election is over, I'd like to sit down with Michelle Rhee and let us walk and talk through it, you know, how we might work together," said Gray on CNN Tuesday.
Rhee had actively campaigned for Fenty. The Washington Teacher's Union actively campaigned for Gray.
"This has been a significant change in direction and its going to require me sitting down with mayor Fenty, the chairman, and other people to see what's in the best interests of our kids," said Rhee on Wednesday in an interview on MSNBC.
I do feel sort of bad and guilty," she said. "This man, Adrian Fenty, is truly the best leader I've ever worked for. We need more leaders like him who are willing to stake everything to make sure our kids are getting a good education."
Obviously, the voters of D.C. disagree. And so do the leaders of local and national teachers unions.
An op-ed Wednesday morning by George Parker, President of the Washington Teacher's Union, and Randi Weingarten, President of the American Federation of Teachers, made no mention of Rhee. The article was titled "No Turning Back for D.C. Kids," and it suggested that the teachers will be happier and work more collaboratively with Gray.
"Public education is a marathon, not a sprint. Yes, there's urgency to fixing our schools, but we have to set ourselves on a long-term path toward constant and sustainable progress," wrote the union leaders.
President Obama stayed out of the race entirely, but his Secretary of Education, Arne Duncan, appeared at an event with Fenty and Rhee in the closing days of the election. It was not a campaign event, but Duncan was announcing the award of $75 million in new federal funding to D.C. schools. He noticeably did not appear at an event with Gray.