If you still early in your game, just don't play too well. Seriously, delay you own progress, don't worry about science or culture, don't worry about favors, don't worry about anything, just play lousy. You want to have a decent amount of favors but there's no need to maximize it, you won't win that vote anyway, don't even try. Do what others recommended in this thread and try to delay the points you get on the tech and civic tree in the future era, you want them to be your two last points. If you do that, all you need is more favors than the AI that have more favors, that isn't a lot. You need to time it right though, if you get 8 points and them take too long to get your last two points, another congress will happen and you will lose a point. You need to research the tech/civic exactly on that 30 turns window between getting 8 points and losing one. You have to cheesy the system to win because it's rigged against you.