The difference is that Borissov has never headed a party before, but he was in the National Movement Simeon II when he was appointed Secretary General of the Ministry of the Interior (he was very loyal to Simeon at that time).

I don't think he'll make it to the President's seat though. Current President Purvanov is strong, will run for office again, and is very likely to get re-elected.
 

I can resist anything but temptation.- Oscar Wilde