Mayor-elect Bill de Blasio drove home two vital points Thursday with his savvy appointment of Bill Bratton to a return engagement as the city's police commissioner.

First, he signaled to doubters that he believes a strong public safety record is key to the city's future -- and that without it, New York cannot fully thrive.

Second, he showed he's not necessarily the ideologue some New Yorkers feared -- that at least on the crucial matter of public safety, he has a pragmatic streak.

Both messages are welcome.

Next, we hope de Blasio will convince the federal courts to let the city reform the NYPD's embattled stop-and-frisk program without the presence of an outside overseer.

Bratton should be able to fix the program himself.

By bringing Bratton back to 1 Police Plaza, de Blasio has recruited a figure who firmly believes stop and frisk can play a major role in keeping the streets safe -- provided it's implemented constitutionally and not overused.

Overzealousness can cost police the good will of the public, and over time, erode their effectiveness.

A federal court recently found that the NYPD resorted to racial profiling during stops and it ordered the outside overseer to ride herd on departmental reforms.

The Bloomberg administration appealed the ruling. It made dramatic headway when the appeals court removed the lower-court judge and put her orders in limbo. Unfortunately, de Blasio has since indicated he'll drop the city's appeal -- which could allow the case to go forward.

That could be a problem for Bratton. As commander of the NYPD, he needs a clear line of authority. Instead, he could have an outside monitor looking over his shoulder and making alternate policies about policing. He also will have a new inspector general scrutinizing his work.

That's a crazy way to run the largest -- and certainly one of the best -- police departments in America. The NYPD can repair its own problems. If de Blasio truly wants to reform the department, he should make sure the federal courts don't handcuff his police commissioner.