In 1963 the Nixon family traveled to Europe, where Nixon gave press conferences and met with leaders of the countries he visited. The family moved to New York City, where Nixon became a senior partner in the leading law firm Nixon, Mudge, Rose, Guthrie &amp; Alexander. When announcing his California campaign, Nixon had pledged not to run for president in 1964; even if he had not, he believed it would be difficult to defeat Kennedy, or after his assassination, Kennedy's successor, Lyndon Johnson.