The blue-chips are those you are comfortable with. In a persuasive the larger portion of your work goes into supporting a certain point of view. Therefore, it is essential you are comfortable with your issue before you begin.
A good exercise is to draft a list of points arguing against the topic you have picked, and seeing if you agree with most of those points.
If not, you have a good persuasive topic in front of you, and are most likely comfortable enough with your stance to make a good public speech.
Remember: the point of a persuasion character is to carry your audience along with you. You will be unable to do that if you are unenthusiastic or unhappy with your topic in the first place.
A consequence that is growing out of and sometimes complicating the problem, cause, alternative, option, plan, or statement you are making is a good way to start. Even consider major developments and progress of the best speech topic you can find.