Yes, the weight of expectation on Barack Obama and the economic cards he was subsequently dealt looks set to erode his mandate and eventually his presidency.
Australia's Kevin Rudd ran on a similar platform of hope, change and reform and, although he made some mistakes on policy and implementation, his political execution from his own, at times, mafia-like party antics led to a premature downfall for his party. Tony Abbott's Liberal Party has no mandate or legitimacy of its own, though, expressing the Australian public's dissatisfaction with both major parties.
Should Abbott form a minority government with the support of a few independent MPs, it will be less of a Liberal victory than a Labor loss.
To ACF94: with proportional voting the Liberal party would hold a clear majority of seats with their primary vote and your vote wouldn't have been wasted, as you so complain. However don't be so indignant with the Labor/Green prefence deal as the Liberal party is part of 'The Coalition' of Liberal, National, LNP and CLP parties (not to mention the conservative FFP, One Nation, Fred Nile's Christian Democrats, et al who always prefence the Liberal Party) and has been so for many decades, sharing continual electrol support among their respective candidates.