When DJ'ing and mixing from one piece of vinyl to the next, it is critical that one be able to gradually sync the respective beats and seamlessly flow from one piece of music to the next. When done well, this can have a surprising effect on the listeners, as the groove can be perpetuated, surprise can augment the impact of good tune selection, and funk is thereby increased.
This is not easy to do. One must have good rhythm, good dexterity in not jarring the very sensitive equipment under time pressure. Even more, to create the proper segue into the following beats requires imagination in proper song selection and an ear for what bumps right. If you screw up, your gear shits the bed, you bonk something or just plain hear it wrong, you get what they call a trainwreck. It's brutally obvious when it happens, brings the whole festival to a stop and creates entire crops of " WTF" faces, all directed precisely at the DJ. It's readily apparent when that happens who gets the blame and there's nobody for it but the guy on the wheels. It is excruciating to watch.
I submit to you that Obama is experiencing a trainwreck that will go on for at least another year. And yet he will probably still win. What does that say about our taste in music?