WASHINGTON -- U.S. Sen. Cory Booker, who has championed efforts to make it easier for ex-convicts to find jobs, opposed a popular airline security bill because he said it would hinder those efforts.

Booker (D-N.J.) was one of only 10 U.S. senators to vote against legislation that would increase checks of airport employees who work in secure areas. The measure was added to Senate legislation setting airline policy and renewing the Federal Aviation Administration for five years. U.S. Sen. Robert Menendez (D-N.J.) voted yes.

Proponents cited the Brussels airport attack and the Islamic State's downing of a Russian airliner.

"Recent terror attacks, along with gun-running and drug-smuggling incidents, are all examples of why much more needs to be done to reduce insider threats to our aviation system," said U.S. Sen. Bill Nelson (D-Fla.), the top Democrat on the Senate Commerce Committee. "If an airport or airline employee can easily smuggle drugs or guns onto a plane, just imagine what a terrorist might do."

Booker, who also sits on the Commerce Committee, expressed concern is that the new checks would provide another obstacle for nonviolent offenders to overcome in seeking to find a job after prison.

"Creating new obstacles to employment for people who committed nonviolent drug offenses more than a decade ago doesn't make our skies any safer," Booker spokeswoman Monique Waters said. "A provision in this amendment expands the scope of when a nonviolent drug offense becomes disqualifying for a job applicant looking to work at an airport."

Civil rights leaders also objected to the proposal. Wade Henderson, president of the Leadership Conference on Civil and Human Rights, told senators in a letter that the amendment "would undermine reforms around the nation that have reduced barriers to employment of people with criminal records, thus representing a serious setback for the bipartisan criminal justice reform movement."

Booker has been a leading voice on Capitol Hill in support of overhauling federal criminal justice laws. He and Rep. Bonnie Watson Coleman (D-12th Dist.) were among the sponsors of so-called "ban the box" legislation that would prohibit federal agencies and contractors from asking about an applicant's criminal history until later in the hiring process.

U.S. Rep. Frank LoBiondo (R-2nd Dist.) is a lead sponsor of the House version of the FAA bill, which calls for shifting air traffic control to a private nonprofit corporation.

Jonathan D. Salant may be reached at jsalant@njadvancemedia.com. Follow him on Twitter @JDSalant. Find NJ.com Politics on Facebook