WI: Republican victory in 2008 and ensuing scenario

So, I've got this idea rolling around in my head: Hillary Clinton gets the Democratic nomination in 2008 and loses to the Republican nominee, presumably McCain. Said Republican makes a mess of things, however, and in 2012 Obama gets the Democratic nomination and wins against the incumbent.

How plausible is this? Are there any greater-scope butterflies stemming from this that I'm missing?
 
It's plausible so long as the financial crisis is delayed. So If there's no crisis in September, Clinton's campaign is a flawed as her's in 2016 OTL, and maybe Bush does his timetable in Iraq before the election rather than after, McCain has a fighting chance. If he wins however, the Democrats will still keep congress as a McCain win would be too narrow to flip either house.
 
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