In the State Department, Kerry quickly earned a reputation "for being aloof, keeping to himself, and not bothering to read staff memos." Career State Department officials have complained that power has become too centralized under Kerry's leadership, which slows department operations when Kerry is on one of his frequent overseas trips. Others in State describe Kerry as having "a kind of diplomatic attention deficit disorder" as he shifts from topic to topic instead of focusing on long-term strategy. When asked whether he was traveling too much, he responded, "Hell no. I'm not slowing down." Despite Kerry's early achievements, morale at State is lower than under Hillary Clinton according to department employees. However, after Kerry's first six months in the State Department, a Gallup poll found he had high approval ratings among Americans as Secretary of State. After a year, another poll showed Kerry's favorability continued to rise. Less than two years into Kerry's term, the Foreign Policy Magazine's 2014 Ivory Tower survey of international relations scholars asked, "Who was the most effective U.S. Secretary of State in the past 50 years?"; John Kerry and Lawrence Eagleburger tied for 11th place out of the 15 confirmed Secretaries of State in that period.

Who complained about how Kerry ran the State Dept?