WASHINGTON – Joe Biden has chosen his longtime adviser Ron Klain to reprise his role as his chief of staff, installing an aide with decades of experience across Democratic presidential administrations in the top role in his White House.That's according to a person familiar with the decision who spoke to The Associated Press on Wednesday on condition of anonymity to avoid preempting an official announcement.Klain served as chief of staff for Biden during Barack Obama’s first term, was chief of staff to Vice President Al Gore in the mid-1990s and was a key adviser on the Biden campaign, guiding Biden’s debate preparations and coronavirus response.