A contestant for Students Union elections and his two supporters were killed as the motorcycle they were using collided with a tractor that was coming from the opposite side on Dalpatpura Road in neighbouring Hanumangarh.All the deceased were aged about 20 years.Police said that Vinod Kaswan who was contesting the election for Students Union in Bal Vikas College was on campaign alongwith Shanker Sihag and Sunil Kumar.The bodies were given to family members after getting post mortem conducted in the afternoon. A case against tractor-drive has been registered.