I am writing an outline for an argument about what I want to be when I grow up, and how I can address a pressing issue by going into this field. I wrote that I want to be a journalist so that I can address inaccuracies in the media. I need an example of political bias in coverage that made a story misleading from a major news organization. I need a source for the example as well.

There have been many examples of media bias in the coverage of the election for the presidency this year. One recent example of bias dealt with the health of Hillary Clinton. The Trump campaign has made many statements about the health of his opponent. If people believe that Hillary Clinton has health issues, this could influence their vote.
Last weekend, Hillary Clinton suffered a health issue after she attended a ceremony remembering the events of September 11, 2001. It was reported and determined that she had pneumonia and needed to rest in order to get better.
When CBS News interviewed her husband, former President Bill Clinton, he caught himself in mid-sentence saying that these medical issues have happened frequently. When CBS News originally ran the interview, the slip of the tongue by former President Clinton was omitted. This clearly changed the dynamic of the story. If people believe that the medical situation last Sunday is a frequent occurrence, they might have concerns about voting for her. If people don’t have that knowledge, they might think this was a one-time, isolated event.
While CBS News did play the full video clip the next day, other news organizations continued to use the original, edited clip. The source I listed provides both the edited and the unedited clip of this interview.
I will give you one other example of media bias. This goes back to the late 1890s and the Spanish-American War. Newspapers, like the New York World and the New York Journal, over exaggerated stories about events that were happening in Cuba. The stories made the Spanish mistreatment sound worse than it was. They also blamed the Spanish for the explosion and sinking of the USS Maine. They also glorified Teddy Roosevelt’s role in the war. He didn’t ride up San Juan Hill. He actually walked up San Juan Hill. These newspaper stories help turn American public opinion against Spain and helped put pressure on President McKinley to have the United States declare war on Spain.
It is great that you have set as your professional goal to work to eliminate media bias. There are many people who think there is too much bias in the media today.
http://users.dickinson.edu/~history/product/fawver/fawver.html

https://mediamythalert.com/tag/cuba/

https://www.studentnewsdaily.com/example-of-media-bias/cbs-edits-bill-clinton/