The push for legislation that would lower prescription drug prices in the U.S. has mounted in recent months, but support for Medicare pricing negotiations has faltered in the past few weeks. Sen. Bob Menendez (D-N.J.) is the latest Senate Democrat to signal his aversion to giving the government the authority to negotiate prices with drugmakers, breathing new life into hopes that the pharmaceutical industry will yet again escape a mechanism that critics say would suppress innovation at the expense of patients in desperate need of state-of-the-art therapies.