Democratic voters will choose from a rich field in New Jersey's Aug. 13 U.S. Senate primary. But Newark Mayor Cory Booker rises above his substantial competitors.

Booker has earned national recognition for his grasp of urban issues, having served as chief executive of the state's largest city with grit and passion since 2006. He could fill a void in the Senate by making a case for America's cities. Based on his record and vision, CORY BOOKER is the Democrat most qualified to become an effective senator for the nation's most urbanized state.

Booker, 44, took on Newark's entrenched political machine and eventually got its backing to unseat the city's corrupt longtime mayor and state senator, Sharpe James. Famously willing to run after a mugger or into a burning building, and to move into the projects and play late-night basketball with kids there, the Rhodes scholar and Stanford- and Yale-educated lawyer grabbed headlines but also restored a sense of hope to the neglected city.

While Newark remains troubled, Booker's record of attracting government and private investment - including new hotels, office towers, and residential development - have put it on a better path.

As a senator, Booker says he would battle child poverty not only by looking to improve educational opportunities, but also with innovative initiatives such as nurse visits to pregnant mothers in the last trimester, which would help put children on a healthy track early in life, preventing unnecessary suffering and health-care costs. His anticrime agenda reaches beyond arresting our way out of the problem to treating its causes.

Booker is a moderate who supports school vouchers as well as same-sex marriage. He won't fill the liberal shoes of the late Sen. Frank Lautenberg, whose death in June necessitated this special election. But his partnership with Gov. Christie proves he can work with Republicans - an essential skill for a successful senator.

Booker's calls for campaign-finance reform would be more convincing if he weren't benefiting from a secretive campaign group, especially since his war chest shows he doesn't need the money. His absence from a recent televised debate was also disappointing.

More importantly, though, Booker has the potential to help chart a path toward reinvigorating America's cities, which have been forgotten by the federal government for too long. He understands that despite their concentrations of poverty, cities can drive innovation, social progress, and artistic and intellectual achievement.

The mayor is running against a highly qualified group in which Rep. Frank Pallone is also a standout. A pragmatic, experienced, statesmanlike legislator from Monmouth County, Pallone is a reliable progressive who knows how to reach across the aisle. He has an excellent record that includes shepherding health-care reform, stopping ocean dumping, financing Shore protection, and updating food-safety measures.

Rep. Rush Holt, an actual rocket scientist, also has strong credentials. A liberal congressman from Mercer County, he is a thoughtful champion of public schools, teacher training, entitlement programs, and privacy.

The fourth candidate, Assembly Speaker Sheila Oliver, has been a dedicated, consistent voice for the state's struggling residents.

Any one of these candidates would vote with New Jersey's interests at heart and often be right on the issues. But Booker's visceral and intellectual understanding of urban affairs, and his exemplary communication skills, make him the best choice for the nomination.