WASHINGTON (AP) _ John McCain’s campaign, trailing topRepublican rivals in money and polls, is undergoing a significant reorganization with staff cuts in every department, officials with knowledge of the shake-up said Monday. Some 50 staffers are being let go, and senior aides will be subject to pay cuts as the Arizona senator’s campaign bows to the reality of six months of subpar fundraising, these officials said. They spoke on the condition of anonymity because the plans have not been made public. An afternoon. conference call was scheduled to announce the results of second-quarter fundraising. Once considered the front-runner for the GOP nomination, McCain came in third in the money chase in the first three months of the year with $13.6 million. He is struggling to reach that total in the second financial quarter. Officials said the fundamental leadership of the campaign will not change; Terry Nelson, a veteran of President Bush’s winning 2004 campaign, will remain campaign manager but may volunteer his time instead of drawing a salary. Nelson declined to comment, and Brian Jones, the campaign’s communications director, did not immediately respond to requests for comment.