I would be more assertive with this concern. Something like "Assaultive behaviors towards fellow citizens should never be tolerated...As a cyclist, I should not have to accept being assaulted and abused." You don't have to be so concerned with being "polite" that you accept abuse.
I just returned from a day of talking to my state legislators in the capitol--something I do quite regularly. The more to the point you can be, the better. I also think it would be in your interest to end with a direct request that the legislator can actually do, such as "Please support complete streets: streets that are safe and functional for cars, bikes, buses, and pedestrians."

