What do Presidents Really Do?

I find it interesting, because every time there's a new one the credit and the blame seem to be put in different places. Either on him or others. I can't really find a good reason for the shifts. So, is it personality? The media? The results?

Take the first president for this current regime, Larry Lucchino. He was the team president and, I presume, ran things at Fenway Park. Underneath him, he had a general manager, Theo Epstein. Generally, it was assumed that Theo was making most of the decisions when it came to the team. The "general managing" if you will. I didn't hear many people give Lucchino credit when things went well. He really only got slammed when things went really wrong. But, I think it was pretty clear that Theo ran the team, and Larry ran everything else.

Then Theo left for the Cubs to become their team president. Chicago was all excited. Theo was coming to change the team, and get them back to winning. At the time, that seemed odd to me. After all, he was going there as president. There was a general manager. Why wasn't he going to be getting the credit? If the team president was really that important, wouldn't Chicago want Lucchino? He's the one who had been team president for multiple World Series winners. Not Theo. I was confused.

Back in Boston, Lucchino went right on being team president over Ben Cherington. Again, Ben got most of the credit, with Lucchino really only ever getting the blame. It was all his decision to hire Bobby Valentine, but all Cherington's decision to sign all the players leading to the 2013 title. It was annoying, but pretty typical. Just like a field manager gets blame but little credit. 

So, maybe that's just a difference between Chicago and Boston? Maybe Boston gave the GM more power over personnel than Chicago did.

But, then came Dave Dombrowski. When Lucchino stepped back from his role, the Red Sox created a new position. They gave Lucchino's President title to Sam Kennedy. Made sense. he was an up and comer in FSG. Then they created a new position, President of Baseball Ops and gave that to Dombrowski. Huh. A new president? Cherington saw the writing on the wall, and went on his merry way soon after the signing. The Red Sox hired Mike Hazen as their GM, and I think that was the last time I've heard his name. Basically every move since then has been credited exclusively to Dombrowski. Whether it was an unpopular one like trading away a top pitching prospect, or a popular one like bringing in a new ace. Twice. 

Suddenly, the Sox had the Chicago mindset. The president was, apparently, making all the moves. The GM was just there to write out the contracts, I guess. Why the shift?

I'd be tempted to say it was because of the talent of Dave Dombrowski. But, Larry Lucchino was no slouch. He should have had a resume plenty long enough to warrant decision making ability. Was he too busy with the Fenway Park improvements to worry about personnel decisions? Did he just not enjoy that aspect of it? Why the change? Was it Theo? Did he grab more of the spotlight than other GMs get? Was it a combination? Was Dombrowski really brought in as GM, but needed to be given the president title to make the hiring work? Would it have looked to bad to fire Cherington, so they massaged the organization by adding a president of baseball ops? How did it happen?

And why?