Obama was also different because he was Hillary Clinton (without an Iraq war yes vote) and a more 'squeaky' clean image. Until the 'socialist' and his connections to 'socialists' came out. Obama, also had a lot more endorsements by delegates, Senators, Representatives, states legislators, governors, etc. If I recall and read correctly Obama had way more money and a much larger operation.
https://www.washingtonpost.com/opin...85377e-2b37-11e5-bd33-395c05608059_story.html
^^ This piece argues why they are different. Mentioning that Obama did not play the 'challenger' role by challenging a candidate to be more and more left leaning and hence allowed Obama to expand his base. He ran a less ideological campaign which again widely expanded his base.
"Sanders’s campaign is
growing rapidly, but even with
new field offices opening fast, it’s still less than half the size of Obama’s organization at a similar juncture in our race: In July 2007, Obama had 80 paid staffers working in 25 offices in Iowa. Obama was able to raise more early money for his campaign; that, coupled with his potential to make history as the nation’s first black president, attracted a very experienced set of advisors with deep knowledge of how to run a sophisticated operation. While Sanders has decided to play the role of the liberal challenger to Clinton, pushing her to the left at every opportunity, Obama ran a much less ideological campaign, which allowed him to build a broader base of support from the outset.
If 2008 is not the best parallel for Sanders vs. Clinton, what is? Probably the 2000 contest between Vice President Al Gore and Bill Bradley. That contest, like this one, was about who would get a chance to succeed a two-term Democratic president. That contest, like this one, was essentially a two-person race (though this could change in the coming months). And in that contest, like this one, the Democratic Party was looking to redefine itself for a new era. Bradley made a surprisingly strong challenge to a sitting vice president, forcing Gore to shake up his campaign, move his headquarters from D.C. to Nashville and retool his entire effort. Ultimately, though, Bradley could not broaden his base of support, and he ended up losing all 50 states to Gore."
