Which representatives should I contact about related issues?

So I recently read these two articles:

• http://www.avoiceformen.com/mens-rights/whats-the-difference/
• http://opinionator.blogs.nytimes.com/2013/06/12/is-forced-fatherhood-fair/

And I wanted to write my representatives about them. Does anyone have experience with this? Are these federal or state issues?