Responsible journalists are required to perform within these parameters, as has been well documented in recent years they do not even come close.
As per Wikipedia - "The principles of Journalistic codes of ethics are designed as guides through numerous difficulties, such as conflicts of interest, to assist journalists in dealing with ethical dilemmas. The codes and canons provide journalists a framework for self-monitoring and self-correction." 
Durring the 2016 Presidential Election some of the emails lifted from Clinton and associate servers prove beyond the shadow of a doubt that large swarths of mass media are in the pocket of the Democratic Party. Wikileaks hacked and released a large number of emails which exposed the shennanigans. For instance, ever wonder why Republican candidates for any office get slammed with loaded, defamatory and difficult questions while Democrats are permitted the skirt any difficulties ?
Lauren Dillon of the Democratic National Committee (DNC) issued a plea to DNC staffers.
To: FreundlichC@dnc.org, BauerN@dnc.org, GrahamC@dnc.org, BennettE@dnc.org, BrinsterJ@dnc.org
Date: 2016-04-28 15:17
Subject: Cruz on CNN
CNN is looking for questions.
Please send some topical/interesting ones.
Maybe a couple on Fiorina.
Someone please take point and send them all together by 3pm.
CNN is looking for questions, that's right questions mind you, - why are they looking to the DNC for questions to ask of a Republican Candidate when it's answers they are supposed to be looking for. And how objective is it to solicit those questions from the opposing party.
Although Donald Trump was the primary target of the shadow party onslaught ...No Republican candidate was immune from the rigged journalistic propaganda machine. Jeb Bush aka "the energizer" was also a target durring the primary period as John Harwood of CNBC not only solicited advice from Hillarys Campaign manager John Podesta but outright took orders from him when he wrote "what should I ask Jeb in Speakeasy interview tomorrow?" 
An "October Surprise" for the Clinton Campaign and Main Stream Media as well came late in the month when WikiLeaks published thousands of Podesta emails. Podesta was Mrs Clintons 2016 Campaign Chairman and one time Chief of Staff to Bill Clinton as well as a counsleor to Barack Obama. Many of these emails further corroborated that most of main stream media was in collusion not only with DNC - but with the Clinton campaign as well.
Some of the media collusion emails involved a woman named Donna Brazile, who to date is the only casualty of the entire fiasco as she was forced to resign from CNN. Brazile undeniably shared questions with the Clinton camp.
In a radio interview on SiriusXM , Brazile said her 'conscience, as an activist, as a strategist, is very clear'. Let me get this straight activist, strategist- I thought she was supposed to be a journalist ? Activist and objective journalist are not reconcilable trades - see ya !
Mark Leibovich, a NY Times reporter, emailed Jennifer Palmieri Clinton communications director and requested permission to use some old Clinton material. Palmieri instructed him to edit out several segments that might be embarrassing to team Clinton. The NY Times reporter gleefully followed orders.
Another hacked email told of a secretive cocktail party being hosted by the Clinton camp for reporters from CNN, NBC, CBS, NYT, MSNBC and so forth, noticeably absent was Fox News.
Kellyanne Conway, Trumps campaign manager and the first woman to manage a successful Presidential election, stated on a 'Fox & Friends' interview that the secretive communiques between the media, the DNC and the Clinton campaign undermine the possibility of free and fair elections.
1. ASNE STATEMENT OF PRINCIPLES
2. Wikipedia - Journalism ethics and standards
3. Wikileaks - Harwood Podesta email
4. 10 questions for Jeb Bush