The particle 嘛 (ma) is a sentence-final particle identical in pronunciation to the simple "yes/no question" particle 吗 (ma) you learned back in the day, but with a rather different function. It can be used when the speaker feels what he is saying is obvious (from his point of view).
Statement + 嘛
An alternate form is:
Topic + 嘛， + Statement
This basically allows the speaker to state the topic, then gather his thoughts before making a comment on it. In this pattern, the following comment may or may not be one the speaker feels is obvious.