HLN on Thursday interviewed a retired New Jersey police officer on the air but blurred out his pro-Trump T-shirt, sparking a discussion about free speech and bias on cable news.

The controversy stemmed from a live segment about 53-year-old Steve Eckel, who rescued a baby from a hot car.

At the beginning of the segment, Eckel's shirt reading "2016 Trump for president" is clearly visible. Later in the broadcast, the shirt's image is blurred out.

Trump supporters erupted on social media and slammed the network for liberal bias.

HLN quickly admitted its mistake.

"We blurred the logo and shouldn't have; it was done in error," the network said.

But the incident left a sour taste in the mouth of Trump supporters and media critics who saw continued evidence of liberal or anti-Trump bias.

A "CNN Newsroom" broadcast on Monday included a tweet from GOP presidential nominee Donald Trump asserting that both he and Democratic presidential nominee Hillary Clinton — whom he called "Crooked Hillary" — should release their medical records.

CNN removed the word "Crooked" from the tweet, leading to charges that CNN is biased in favor of Clinton.

CNN — the parent network of HLN — apologized for that incident as well. "The tweet should have been shown in its entirety," a network spokesperson told the Hill.

CNN and HLN are both owned by Time Warner. CNN has become a target of many of Trump's jabs in recent months.

Is their a link between Trump's taunts and the network's coverage of him?

CNN has stepped up its use of chyrons — electronic captions at the bottom of the TV screen — to fact-check Trump's statements.

But Trump is an unusual candidate: 53 percent of his statements rank as "False" or "Pants on Fire" in Politifact's scorecard. Only 13 percent of Hillary Clinton's statements achieved these ratings, according to the fact-checking outlet.

Bias only serves Donald Trump and feeds into the narrative about unfair liberal media.

When a cable news network makes a mistake of bias against Trump or his supporters, it ignites a backlash from the alt-right and plays into Trump's argument that the media are out to get him.

You can watch the clip on Youtube below.