Political science and practical politics are very different things. This is why most political scientists are not politicians and most politicians are not political scientists.
Political scientists study various aspects of politics in their country. They tend to study very narrow areas. For example, the author of this article is looking specifically at arguments made to justify cutting social welfare benefits. They often study abstract issues. For example, the author of this book is writing about why the political party system is fair and useful in our system. Writing these articles does not necessarily prepare political scientists to be politicians. The author of the first article may know why some of the arguments about cutting social welfare programs are wrong, but to be a good politician he would have to be able to convince people who believe in these arguments that they are wrong. Knowing something in your own mind is very different than persuading someone else. The author of the book about political parties might not know anything about what policies are actually good for the US; he is just writing about political theory. Thus, studying political science does not make one a good politician.
The opposite is also true. Politicians generally need to be good at a couple of things. They have to be good at making people want to vote for them and they have to be good at raising money. Being good at these things does not make them smart in the way academics need to be smart. It also does not mean that they would be interesting in studying abstract ideas.
Political scientists and politicians do not need to be good at the same things. Therefore, the fact that you are able to be good at one thing doesn’t mean you would be any good at the other.