Running the White House in a normal environment can be overwhelming. But the affable 44-year-old routinely finds himself rushing down the hallway from his office to intercept unscheduled visitors to the Oval Office.
If running the White house in a normal environment can be so difficult and the 44-year-old became busy because of that, then why there is a but in the beginning of the sentence? Wasn't "but" used to say when some two situations are contrary? Or Am I just misunderstanding these parts of article completely?