Fame
Most political scientists never know fame. They push paper and earn their paychecks, just like everyone else.
However, there's always the chance that you could end up with your face plastered all over the news. Maybe you come up with a really amazing theory on how to get more Americans to vote. Maybe you write a tell-all book about your time spent working for a presidential campaign. Maybe you pull an Edward Snowden and leak classified information to the press.
In other words, depending on the path you choose, you as a political scientist could become famous. You could also end up in serious trouble with the intelligence community.