There was a more "left" candidate - Dennis Kucinich. He never broke 10% (despite my vote). The vast majority of Democratic voters picked a "moderate".  So why one would expect such a selection to result in a left wing government puzzles me. It seems often to be a kind of assumption about one's own privilege.

The other weird thing about the disappointeds is that most of them are highly engaged, at least emotionally, in the political process, but they don't seem to understand the basics of how either the formal or informal power structure works. The US system give legislative power to Congress and Congress is elected via open primary and then general election - locally by state or district. Thus, Congress is not at all beholden to the President. There is no party list. For example, Mary Landrieu is a powerful senator from Louisiana who knows that Obama received 40% of the vote from her state - to be re-elected she must appeal to a conservative electorate (and to local powers in the oil industry). So a President has some leverage, but not the ability to force votes - especially a Democrat who does not have organized business groups to assist. In recent US history, neither Jimmy Carter nor Bill Clinton were too successful getting liberal legislation through the Congress. So that's the formal problem. Of course the informal problem is that no US president can simply defy the actual power elite- the corporates, the imperial military, the permanent government - he or she must try to form alliances, to split opponents etc.  What I have found most odd about the "disappointeds" is that many of them claim to be on the left, but have absolutely credulous theories about how the imperial system works - e.g. "the President is the commander in chief, he can just order the military to do so and so".

just for myself, when Bush's helicopter left DC, it was enough for me to call the Obama administration a success.