Which has better job opportunity, a degree in Sociology or Political Science?

Political science.  It will be easier to pursue a job or further education in the following areas:
1) Law
2) Law enforcement
3) Government / municipalities

These are better paying, more stable fields than "generalist" jobs you would get after getting a sociology degree.

Sociology will be difficult to have a strong career without going to grad school. I know plenty of sociologist that work with consumer behavior as specialist with external decision making. You will do more research than anything.

Political Science can be a great career right out of undergrad if you are motivated to move to DC and get first hand experience.

You could probably major in PoliSci and get a minor in Sociology and use them both to help candidates develop a better idea of what external factors assist in a voters decision. There is a process they go through before marketing to certain electoral states.

Good Luck!

With sociology you can become a case worker, thats 21K to 35K

You can teach high school with another 6 months school and testing.  21K to 35K depending on area

You can be a manager at K-Mart or Target $30-35K