> I don't think it's fair to say he lost interest in it. It's a combination of 1) having less power than people think; and 2) having to be everyone's President, not just the people who elected him.
I think its mostly #1, combined with the fact that reform was behind a few high-priority economic issues, and by the time they were taken care of, Congress was embroiled in campaigns for the midterm elections, where the Democratic majority fell to a Republican majority unusual (even in the history of divided government in this country) unwilling to work with the President (Mitch McConnell, famously, stated that his #1 priority as Senate Majority Leader was to assure that Obama was a one-term president), which meant there was no way for any reform agenda Obama had to make progress.
> If you were President and had a good faith desire to govern by national consensus, what would you do?
I don't think any President has had a good faith desire to govern by national consensus (nor do I think that governing by national consensus in the US, at any point in its history, would be a reasonable or even sane desire.) OTOH, Presidents have very little practical choice, on certain matters, other than to operate within the constraints set by Congress' willingness to participate.