When you call your representatives, remember to remain calm and polite. I know how politics can get our blood boiling sometimes, but it's important that they realize we're rational, responsible parents who only want the best for our students.
Also, it's important to give reasons why you're against the bill (testing isn't the best way to measure learning, especially for homeschooled students (see my FAQs for information about testing: http://www.carolinah...r.com/afaq.html) and that one association cannot possibly meet the needs of all homeschoolers. Having one named in the law creates a monopoly and denies us choice.
Add any other reasons you are against the bill.
If you write an email or letter, make sure someone else looks over it to check for spelling and grammar errors. A long-time homeschooler shared a story a while back about a newspaper article featuring a homeschooling family. It was very positive. However, the paper received dozens of letters about the misspelled word the homeschool mom wrote on the chalkboard (it was in the photograph next to the article). It totally negated everything positive about the article. Only one letter to the editor was in support of homeschooling due to that misspelled word. Everything else was very negative.