Keller @ Large: The Worst Job In America

BOSTON (CBS) -- What is the worst job in America? Septic tank emptier? Toxic waste cleanup specialist? Journalist?

How about White House chief of staff, the ultra-stressed, short-term employee in charge of managing the day-to-day affairs of the most powerful person on Earth?

The White House chief of staff - sometimes known as the gatekeeper - has only existed under that title since 1953, and the average tenure has been a bit more than 18 months.

George H.W. Bush went through three chiefs of staff in four years.

Ronald Reagan and Bill Clinton each had four during their eight years in office.

But it seems President Trump is on track to leave all of them in the dust. Reince Priebus set the record for shortest stint of a president's initial chief of staff when he was bounced after 192 days.

And now John Kelly, who just passed Preibus in length of service, may be on thin ice amid an uproar over his handling of accusations of domestic violence against now-departed White House Chief Secretary Rob Porter.

Why do White House chiefs of staff seem to have such a short shelf life? In part because they have to oversee a collection of huge egos, and protect the interests of the president, which may or may not align with the interests of others in the White House.

General Kelly, a widely-admired former Marine, is on the banana peel because he initially circled the wagons around Porter, and may not have been candid about what he knew about the aide's alleged misdeed or when he knew it.

This wouldn't be the first time a chief of staff couldn't balance his boss's agenda with truth and justice. And it surely won't be the last.

Share your take with me via email at keller@wbztv.com, or on Twitter, @kelleratlarge.