I think that Obama was further to the left than Clinton on a number of issues, possibly most importantly on the issue of war with Iraq. When Hillary Clinton voted for the war, Barack Obama was speaking out against it. Clinton has yet to even apologize for the vote the way John Edwards has.
The primary has been rough for progressives. It seemed at times as though the Democratic Party had Balkanized into identity based politics. In an election that so strongly favors the Democrats, the split of whites, women and Latino's for Clinton and youth and Blacks for Obama, has made many doubt if the party can come together. Hopefully the adage about the Democrats being able to snatch defeat from the jaws of victory will be proven wrong.
My mom was a big supporter of Clinton, while I was leaning towards Obama. Those polls that showed older women going for Clinton and young college educated youth going for Obama don't lie. I didn't understand why my mom liked Clinton so much until I read The Feminine Mystique by Betty Friedman. It describes the pain so many mothers feel, in taking care of everyone but themselves. Clinton was a woman who was able to make something of herself outside of raising a family, which is why so many women looked to her as an inspiration.
I was leaning towards Obama, but I think one of the things that sold me on him was the campaign Clinton ran against him. The now infamous 3 AM ad that Clinton approved was a real attempt on her part to portray herself as a hawk. Her attempts at racializing the campaign in states like Indiana and the Carolina's was also disturbing. She had Bill go to Vegas and work against unions on the Vegas strip, with the help of general managers in Vegas.
However, there is a big difference between Barack Obama the candidate, and Barack Obama the movement. Many of Obama's grassroots and netroots supporters are much more progressive than he is. In some ways I'm more interested in the progressives on his campaign more I am Obama. Even Obama admitted to his staff after his victory, that when he started the campaign he wasn't sure if he was the best candidate, but he was sure that he could put together the best political organization. As far as the primary goes, it certainly seems as though he has.