I have no idea what happened, or didn't happen, in Cartagena last week when at least 11 Secret Service Agents were suddenly sent home and replaced by a different team.
You've read the headlines: "Agents Procure Prostitutes While Waiting for Obama" or words to a like effect.
A hundred years ago I did a few advance trips for Vice President Quayle. You can argue, and successfully, that the whole notion of putting about 100 people in place up to two weeks ahead of a visit by a President isn't so much presidential as it is as it is imperial, but that's a discussion for another day.
This is not something President Obama invented. I'm not sure when it started but it was the Presidential advance staff that arranged events at which Franklin Delano Roosevelt was appearing such that the public couldn't easily see that he was unable to walk due to having contracted polio.
Was that a good thing or a bad thing? I don't know because 1939 is not the same as 2012. The press knew perfectly well that FDR was (as they said at the time) crippled, but they didn't report it. Today there would not be a Presidential event that didn't include people - children especially - within the frame sitting in wheel chairs.
In 2012, not only would everyone know the President was handicapped, but it would be turned into an asset.
There are three principal aspects to a Presidential advance operation: Politics, Policy, and Security.
The Security is the province of the United States Secret Service which was established on July 5, 1865.
Until March 1, 2003 when it was transferred to the new Department of Homeland Security, the Secret Service was a subsidiary of the Department of Treasury. It still has primary responsibility for currency scams including counterfeiting and credit card fraud.
Politics and policy are the province (how's that for illiteration?) of the White House. Oh, wait! This is better:
Politics and policy are the principal province of Presidential personnel.
There is a small Office of Presidential Advance. Most of the other people who go out in advance of a Presidential visit are federal employees from other organizations or, as in my case, volunteers who think its cool.
Advance operations also include military personnel. There are Air Force meteorologists and Air Force One coordinators. There are also, depending upon the venue, other branches of the military involved. WACA - the White House Communications Agency - staff are typically Army technicians.