02/20/2009 05:12 am ET Updated May 25, 2011

Presidential Security

Ever since the assassination of John F. Kennedy in 1963, security measures for our presidents have become virtually airtight. Occasionally, a breach occurs as did John Hinckley's bullet aimed at Ronald Reagan in 1981 and Iraqi reporter Muntadhar al Zeidi's shoe aimed at George W. Bush in 2008.

The security for today's inauguration of Barack Obama, already heightened because of the event's exposed activities, has been heightened still further by "threats against him and intensified racist commentary on Web sites used by white supremacists," as David Johnston reports in the New York Times. Johnston goes on to describe the $50 million security effort that will seal off the District of Columbia by closing all roads and the five major bridges to the city while fighter jets provide air cover and Coast Guard boats patrol the Potomac River and "teams of intelligence analysts, evidence response technicians, bomb experts, cybersecurity specialists, hostage negotiators, emergency medical personnel and SWAT units" are deployed.

I had my own foretaste of the level of security on Friday in Philadelphia. I was in the city to deliver a keynote at a University of Pennsylvania Graduate School of Education event, and then headed to the airport to return to San Francisco. During the taxi ride south to the airport, the northbound lane suddenly came alive with flashing red, white, and blue lights of a motorcade of more than two dozen vehicles police cars, motorcycles and black SUVs that went zipping past, doing 50 or 60 miles an hour. I asked the driver what it was all about, and he replied, "Obama!"

Only later, when I picked up the Wall Street Journal at the airport, did I learn that Obama was in Philadelphia to begin a whistle stop train trip "intended to reflect the inaugural voyage of fellow Illinois lawmaker Abraham Lincoln, who rode 12 days from Springfield, Ill., on the way to his 1861 inauguration."

But the balance of my ride to the airport made the high level of security to protect the President-elect indelibly clear: for miles the northbound lane was an empty ribbon of concrete. Every entrance and exit ramp to that lane was barricaded by a pair of police motorcycle officers.

The Secret Service is doing its job.