The shelf life of a D.C. school superintendent is just over two years.

Gen. Julius Becton quit in 1998 after a couple of years, Arlene Ackerman fled after two in 2000. Paul Vance stuck it out for three and left us with this immortal line: "To be very candid with you, I just don't want to be bothered with it." Clifford Janey came and went before his third anniversary.

Schools Chancellor Michelle Rhee celebrates her second anniversary this summer as public school boss. For those who wish she would pack up her box of reform tools and take them upstairs to the Obama administration -- or back to Denver -- fuggedaboudit.

Rhee is here for the long haul. She's counting on Adrian Fenty getting elected to another term, which would give her six more years to remake the schools. "At the end of the second term," she tells me, "there's a good chance the achievement gap between white and black students will be closed."

For 50 years the system had been crushing the souls of youngsters. Principals ran fiefdoms of favorite teachers; buildings collapsed on students; teachers abandoned their classrooms; nepotism ruled the downtown administration. Still, Rhee's critics demand she prove results -- now!

For 50 years the system had been crushing the souls of youngsters. Principals ran fiefdoms of favorite teachers; buildings collapsed on students; teachers abandoned their classrooms; nepotism ruled the downtown administration. Still, Rhee's critics demand she prove results -- now!

Last week Rhee and Fenty rolled out assessments from the 2009 school year. Preliminary results showed students scored better in reading and math tests. Mind you, even the best scores are still shameful: The percentage of elementary school students proficient in reading rose 3 percent from last year, but the number is still 49 percent.

But make no mistake about it: school reform is succeeding. It is not a stretch to say that reform efforts here are more radical than in any other city; if successful, they could become a blueprint for all urban school systems.

Keep in mind that D.C.'s charter school movement is the most robust in the nation. The city has 60 charters, financed with public funds but independent of the public school system. About 50,000 students are enrolled in public schools; about 26,000 go to charters.

Last week's test results showed students in charter schools are improving at faster rates than those in public schools. But comparisons are not fair. Charters are zippy speed boats compared with the rusting tanker with Rhee at the helm.

Rhee said there was no one thing that produced better results, but there are a few signs. "Test scores of schools with new principals outscored the District average," she says. "We did the right thing by replacing principals."

Rhee forced schools to identify kids who needed help, test them, drill them, bring them to school on weekends and after class. Sounds obvious, but it took Rhee to get it done. "Still," she says, "I am not sure the quality of instruction has improved."

Rhee says her biggest disappointment is that she hasn't been able to fix everything in two years. What's most heartening? "I am positive these children will be able to do all the things people say they can't."

But it will take six more years to prove it.