win by a landslide

To win (something) by a very large and decisive margin. A noun or pronoun can be used between "win" and "by." Everyone thought it would be a close game, but with a 45-point lead heading into the last two minutes, it looks like the underdogs are going to win it by a landslide. Her candidacy seemed like a long shot from the very beginning, but she kept growing in popularity leading up to the election and ended up winning by a landslide.