You can't. I got a science victory on emperor, would have been a diplo victory in a few more turns but I felt good that I launched BEFORE the WC vote. To be honest, the only reason I did it is because it's more satisfying to see the rocket blast off than to click a bunch of delegates. I hope in the patch they require more in the "diplo" victory than achieving economic domination of city states. I, too, agree that there should be a prohibition on voting for one's own civ, and perhaps not have the city states vote at all. That way only the truly best diplo player will win. As another post stated, you can be a terrible diplomat and just buy city states and get the diplomatic victory. The thing is when you're TRYING for the diplo victory, obviously the world leader vote can't come soon enough. I think going back to the previous version, make someone build a wonder instead of it automatically being triggered, would improve it. I have to say, the graphics for the victory screen have GOT to improve. The wonder videos are nice. Shouldn't it look "cooler" to win the game than to complete a wonder?