The Biden Administration has called for a new investigation into a possible Wuhan lab leak of the Covid-19 virus. The Trump Administration had made the same claim but was largely dismissed by the news media on the grounds that the former president's words are not trustworthy, thus the claim (by Trump) could be another false accusation the same as the claim by G. W. Bush and Tony Blair of “weapons of mass destruction” in Iraq. These are some examples of controversial things the media has reported about, and with these things, come inherent political bias.

My question is, as influential as it is, what mechanism (if any) is there for the checks and balances on the news medias inserting political bias on news coverages.

I apologize for my poor English. Suggestions or outright editing are welcome.

Some examples of controversial media posts with bias: