WASHINGTON -- A U.S. Supreme Court decision making it harder to prosecute public officials could help U.S. Sen. Robert Menendez as he fights federal corruption charges.

A unanimous court threw out the conviction of former Virginia Gov. Robert McDonnell, who had accepted gifts, loans and vacations from a Richmond businessman while arranging meetings for him for state officials and praising his product, a nutritional supplement derived from a substance found in tobacco.

"The Supreme Court has narrowed the application of the official act definition in the laws so it does not apply to the normal day-to-day activities of public officials," said Menendez's lawyer, Abbe Lowell. "We are looking carefully at the court's decision and the allegations and the charges against Senator Menendez and believe that the Supreme Court's case should have some impact."

In the case of McDonnell, the court ruled that the former governor's activities on behalf of his patron were not considered "official acts."

"Setting up a meeting, talking to another official, or organizing an event (or agreeing to do so) -- without more -- does not fit that definition of 'official act,'" Chief Justice John Roberts Jr. wrote.

The decision "makes public corruption prosecutions much, much harder," former federal prosecutor Melanie Sloan said.

Menendez was indicted on 14 counts in April 2015 for allegedly accepting trips and campaign contributions from a friend and donor, Dr. Salomon Melgen, in exchange for intervening with federal agencies on his behalf.

The senator had contacted the Centers for Medicare and Medicaid Services, which found that Melgen had overbilled the government by $8.9 million; asked about a port security contract in the Dominican Republic held by a company whose investors included Melgen; and helped support visas for Melgen's girlfriends.

Menendez's case is different because he took more specific actions than McDonnell, Sloan said.

"He was exercising influence, even under the new McDonnell standard: Issue the visa, change this Medicaid reimbursement thing," Sloan said.

On the other hand, Gerald Krovatin, a veteran criminal defense attorney in Newark and former president of the Association of the Federal Bar in New Jersey, called the decision "only good news" for Menendez.

"You're allowed to make phone calls, you're allowed to schedule events, you're allowed to talk to other public officials in government.," Krovatin said. "The court says that's what we expect public officials to do."

The Third Circuit Court of Appeals is deciding whether to dismiss the charges on the basis that Menendez's actions fell under the Constitution's speech or debate clause, which protects legislative activity.

Should the appeals court reject Menendez's arguments, his lawyers could then ask the presiding judge, U.S. District Judge William H. Walls, to throw out the case on the basis of the Supreme Court decision.

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