There is no doubt that the Presidential style of campaign started when television really took hold.  Probably the first definite example was when Hawke was leading Labor. The previous leaders, Whitlam and Fraser, were both up there, but not in the way it has been since.
Aaron is, of course, correct in his description of the electoral process, but it's the campaigning that has been twisted. The unfortunate effect, and you'll hear it everywhere, is "I'm voting for Abbott / Rudd."