What constitutes a landslide victory?

[Todd Whiting]

I am doing some research prior to writing a letter to the editor of my loacal newspaper. What percentage of the vote constitutes a landslide victory?

I would like to comment on a local race wher one candidate won with 65% of the vote, and the challenger recieved 35%. I don't want to refer to it as a landslide if it does not fit the bill.