Could be. I had one guy continue to tailgate me after the road widened to two lanes.
I've experienced this also. I can think of multiple reasons why they would do this other than being jerks:
1. Some people don't seem to be able to drive independently.
2. They are on their cell phone and can't talk and drive at the same time, so they just zombie in on your car's butt, letting you take all responsibility for what happens. I think this type is sentient enough to recognize non-psychotic drivers that are safe to follow.
3. They are my sister. I once had to tell her, while she was tailgating someone in front of us, that the person in the merging lane might need more than 6 inches of space, in order to do that.