There's a big difference between donating to a politician because you want to pollute more and donating to him because you know his opponent has every intention of imposing a carbon tax scheme on the country in order to provide a global government with a means of raising revenue and imposing rules without the consent of the governed.
There's a big difference between donating to a politician because you want to pollute more and donating to him because you know his opponent's party's leader has stated openly that they intend to destroy your industry domestically. Sourcewatch lacks the ability to show intent.
Who else could they donate to given the opposition?