By August his campaign's messaging had become confused due to staff rivalries, and in September, he was accused of plagiarizing a speech by British Labour Party leader Neil Kinnock. Biden's speech had similar lines about being the first person in his family to attend university. Biden had credited Kinnock with the formulation on previous occasions, but did not on two occasions in late August. Earlier that year he had also used passages from a 1967 speech by Robert F. Kennedy (for which his aides took blame) and a short phrase from John F. Kennedy's inaugural address; two years earlier he had used a 1976 passage by Hubert Humphrey. Biden responded that politicians often borrow from one another without giving credit, and that one of his rivals for the nomination, Jesse Jackson, had called him to point out that he (Jackson) had used the same material by Humphrey that Biden had used.