Labor is screaming over biased reporting in News Corporation titles. But does the endorsement of Rupert Murdoch and his editors influence the outcome of elections? The chequered record of editorial backing by Murdoch's three major mastheads since the 1970s suggests a muted influence, at best, according to a Crikey search through the dusty archives ...

Since the constitutional crisis of 1975, The Australian has officially endorsed eight successful candidates and five unsuccessful leaders -- abstaining in 1996 when John Howard came to power. In an editorial column published every Friday before the nation heads to the polls, The Australian has endorsed 11 Liberal leaders and only two from the Labor side -- Kevin Rudd in 2007 and Bob Hawke in 1984. Rodney Tiffen, an emeritus professor at Sydney University, told Crikey it's no surprise The Australian endorsed these two Labor candidates, given Rudd went on to enjoy a 23-seat swing in 2007 and Hawke prevailed over Malcolm Fraser after eight years in office. "Occasionally the Murdoch press gives qualified and tepid support to Labor, but only when it's likely that Labor are going to win," said Tiffen. "When they give support to the conservative side of politics it's all out and wholehearted -- that's what we've got with The Daily Telegraph this year." There are no tepid endorsements at the Herald Sun. Melbourne's most-read newspaper has endorsed Liberal candidates at every federal election since the merger of The Sun News-Pictorial and afternoon broadsheet The Herald in October 1990. Four of these candidates proved to be winners, with the other three losing the election held on the following day ...