As politics has become increasingly more partisan, it is vitally important our news organizations report without bias. Every decision, from selection of news stories to how the story is being told, will be heavily scrutinized and is why newsroom personnel should avoid expressing political opinions anywhere, particularly on social media. Each organization will risk credibility when these rules are not followed.
Here are excerpts from The Associated Press Statement of News Values and Principles that relate to conflicts of interest and political reporting and published in The AP Stylebook.
Here is a downloadable copy of the Society of Professional Journalists Code of Ethics. Additionally, this link offers a position paper on political involvement.
The New York Times Ethical Journalism handbook is also a great resource. Excerpts are available here.