Hillary Clinton 2008.
At this point Trump's surpassed Giuliani and Dean analogies.
Yup. That's about the closest.
One big difference this time is the mood of the respective electorates. In 2008, Democrats still had respect for their party's leadership, so that factor didn't largely influence primary voters' choices.
In this cycle, the mood of Republican voters is significantly different. They see 2012 as an election that was eminently winnable - one that was lost under the guidance of incompetent party consultants, leaders, strategists, etc. They see the conservative legislative achievements (or lack thereof) from the 2010 and 2014 elections as a mixture of betrayal and incompetence. They
loathe their party's leadership - leadership who directed its candidates to run on a very specific, strong platform of Conservative Causes X, Y, Z, etc.. - so when party officials, GOP-leaning pundits, elected leaders, etc predict doom that comes with a Trump nomination.. their voters don't give those warnings much credence, as the warnings are coming from entities with no credibility on the topic of "
Winning."
Trump sensed this mood and seized on it brilliantly. Whenever someone attacks him, the GOP's voters now see these attacks and wonder, "why should we trust you? You let Obama walk all over us, you lost 2012, and you have no credibility." In the modern era, we haven't seen anything quite like this.