Sometimes it pays to learn from your opponent. In order to get to the position of power to implement the changes you want, you will have to ruthlessly take out road blocks that are in your way.
Obama should not hesitate to take Hillary out. His campaign should point to the Clintons's history of hurting the Democratic Pary:
Shame brought on to the party by the Lewinsky scandal
Bill's use of the White House as Motel 1600
Bill's administration's trashing of the offices on their way out
Bill's failure to stop Osama Bin Laden early on
Hillary was a party to all that. Bill is her biggest liability and will be a liability to the nation if they get back in the White House.
Much of the economic euphoria during Bill's presidency coincided with the stock market boom. The Clintons should not get all the credit for that.
The blue collar voters that makes up Hillary's base can only relate when things are spelled out clearly for them.
After Obama's done with Hillary then he should throw the kitchen sink at McCain. It may be crude but there's no escaping it. To gain power you have to exercise power. Again, those like the blue collar voters only respect toughness and explicit power.
Obama should be glad that at least in our blessed country he does not have to resort to purges to get to the position of power. But make no mistake, he has to go out and take the bull by the horns and shake it until it submits.