Both the fields needs quite a number of educationists be it Teachers/ Researchers/ Professors/Lecturer's. So the field you will choose have quite a good demand. Now there are some advantages in English over Political Science. If you do MA in English then even if you don't continue for the PhD then also you have several openings in the Journalism, Content Writing industries. But for the Political Science such scopes are not that much broad. If you are determined to be a professor, then you need to do a PhD and for that really getting enthusiastic about the subject is important. So choose the subject, which interests you the most & keep studying.

For more information regarding English you can consider the link below:

https://www.careers360.com/courses/english-course

For more information regarding Political Science you can consider the link below:

https://www.careers360.com/courses/political-science-course

I hope this helps. Wish you a great eve!