Odds of Hanging On
Unless there's a radical shift to dictatorship, democratic elections will be the norm for a while. So there will always be a steady crop of would-be leaders who need help putting their campaigns together. Retention in this industry comes down to your track record. If your candidates win a lot, you're gonna be sitting at the popular table.
If not, well, hopefully it's only a minor setback on the way to your next big victory. Don't give up—plenty of campaign managers can and do recover from a few losses.
Looking to move on? Campaign managers can work in a variety of fields, and are well suited to advertising, public relations, and consultation. Many end up going into the political arena themselves, if they haven't done so already. Maybe one day you'll need an election manager of your own.