who's broken enough campaign promises (close gitmo! Stop military tribunals of suspected terrists! Get out of Iraq! End welfare for the rich!) to lose 3 re-election bids.
Has he?
He's trying to close gitmo but first he had the issue of figuring out where to move the prisoners nobody wants them. The nobody wants them issue exists on two fronts. There are the prisoners we want to release but we can't send them back to their country of origin due to likelihood of torture or that country doesn't want them. This group is likely largely innocent but nobody will take them anyway. Then there is the group of people we want to continue to hang onto. He's tried moving them inside the country but has met resistance with local governments as to location of the prisoners.
As far as stopping the tribunals, he's also tried to do this. However, Congress is trying to block funding for moving the prisoners out of Gitmo which makes it difficult to try them in a normal criminal court. This also makes it hard to close gitmo.
We're drawing down troops in Iraq. At this point we officially only have military advisors to the Iraqi's there. Even these advisors are slated to leave unless the Iraqi's ask us to stay. They've signaled they have no intention of doing that. So I think it's pretty safe to say this is largely a promise kept. Maybe it isn't on the time frame you'd like but it is in progress.
As to your last complaint about ending welfare for the rich, I'm not aware of where he promised that. Nor is it really clear what you mean by that. It could take on many different meanings.
Now if you want some legit things to complain about here are some things to point at Obama that he is actually responsible for:
Indefinite detentions using Afghanistan as opposed to Gitmo.
Ordering assassinations of US Citizens without trial.
Supported the immunity for telcos for spying (technically while he was a Senator but his administration is continuing to uphold this).
There are legitimate arguments to make that Obama hasn't been as great as many people would have hoped, but as far as I can see he has largely upheld his campaign promises to the degree that he has been able to carry them out in spite of active efforts on the part of Congress to prevent them.