Why are jacked up or lifted SUVs legal on the road?

I was driving my Honda Civic today in bumper to bumper traffic when I started getting tailgated by a lifted SUV.

All I could think was, “If there is an accident, that thing will go right over my trunk and remove the entire roof-top of the car, along with everyone in it”. It would be bad enough to get into an accident with another car, or even a half ton SUV-truck, but, these vehicles seem even more dangerous than the average SUV-truck. How is this legal?