[167] The New York Times reported that the strategy behind the choice reflected a desire to fill out the ticket with someone with foreign policy and national security experience.[168] Others pointed out Biden's appeal to middle-class and blue-collar voters.[169][170] Biden was officially nominated for vice president on August 27 by voice vote at the 2008 Democratic National Convention in Denver.[171]
Biden's vice-presidential campaigning gained little media attention, as the press devoted far more coverage to the Republican nominee, Alaska Governor Sarah Palin.[172][173] Under instructions from the campaign, Biden kept his speeches succinct and tried to avoid offhand remarks, such as one he made about Obama's being tested by a foreign power soon after taking office, which had attracted negative attention.[174][175] Privately, Biden's remarks frustrated Obama. "How many times is Biden gonna say something stupid?"he asked.[164]: 411–414, 419  Obama campaign staffers called Biden's blunders "Joe bombs" and kept Biden uninformed about strategy discussions, which in turn irked Biden.[176] Relations between the two campaigns became strained for a month, until Biden apologized on a call to Obama and the two built a stronger partnership.