As someone who lives in Newark and had significant business with the city during Booker's tenure, I can tell you he is a poser and that Newark was a convenient stepping stool to whatever was next for him. Former Gov. Christie headed him off at the pass during his second term re-election bid courtesy of Sen. "Uncle Frank" Lautenberg kicking the bucket right on cue which resulted Christie nominating him to fulfill the unexpired term. Booker should NEVER be in charge of running anything ever again.
1. Racial economic inequality did not improve in Newark.
2. Newark Police Department operates under a DOJ consent decree due to excessive and repeat racial profiling police tactics during his tenure (to be fair they existed prior to him being mayor).
3. Newark has structural property tax issues due to long term tax abatements that his administration gave away like candy.
4. Newark Public Schools were under state control for 20 years. Booker cooperated with Christie, the state education commissioner, and the district superintendent to convert 40% of the schools to charter-closing neighborhood schools.
5. The Newark Watershed scandal
https://www.politico.com/states/new-jersey/story/2016/01/newark-watershed-corruption-staggering-even-to-jaded-observers-029688