At issue are the curious dealings between Mr. Menendez and his close friend and benefactor Salomon Melgen, a wealthy Florida eye surgeon and major Democratic donor. The senator’s efforts to help Dr. Melgen, part-owner of a firm that had a long-dormant contract with the Dominican Republic to provide port security, revive that lucrative contract — deemed an exorbitant giveaway by business leaders and government officials there — were detailed in an article in The Times last week by Raymond Hernandez and Frances Robles. The contract’s dubious legitimacy and Dr. Melgen’s lack of experience in border security issues did not deter Mr. Menendez from pressing State and Commerce Department officials to insist that the contract be honored, including at a hearing in July of the Senate Foreign Relations subcommittee over which he presided…

It appears Mr. Menendez has learned little from his own previous ethics issues or from the fall of a former New Jersey senator, Robert Torricelli, who decided not to run for re-election in 2002 amid allegations that he had inappropriately aided a big donor and accepted expensive gifts. It is unclear whether the Senate Ethics Committee has initiated a formal inquiry into Mr. Menendez’s conduct, but a prompt and thorough review is surely called for. In the meantime, Mr. Menendez needs to relinquish his leadership role, at least temporarily.