The Media Research Center thought it might be instructive to compare news coverage of two infamous presidential endorsements — the endorsement of Donald Trump by former KKK leader David Duke and the endorsement of Hillary Clinton by the pro-Taliban father of Orlando jihadist Omar Mateen — to see if perhaps there's a little bit of political bias in the mainstream media.

Surprise! There is. A lot. In fact, if you're going to put a number on it, there's about a six-to-one bias in favor of Democrats. Sounds about right.

"During the first three days of coverage after David Duke, a white supremacist and former leader of the KKK, endorsed Donald Trump back in February, the evening news shows on ABC, CBS and NBC devoted 11 minutes and 35 seconds to bashing Trump for not immediately denouncing Duke, after he already had," reports NewsBusters.

So how did those same networks handle the endorsement of Clinton by Seddique Mateen — who espouses pro-Taliban, anti-American views and posted a video declaring "God will punish the homosexuals" a day after his son shot over 100 people in a gay nightclub — and his appearance right behind Clinton (perfectly positioned for lots of camera time) at a rally in Florida? Apparently, that was not really a story, despite Clinton not fully disavowing his endorsement initially, and the incredible fact that she was specifically talking about Mateen's son's horrific attack on a gay nightclub at the rally as he sat just a few feet away.

Both ABC and CBS essentially dismissed Mateen's stunning appearance and vocal endorsement of Clinton as "coincidence," devoting a total of 1 minute and 54 seconds to it, while NBC refused to cover the story for a full day. When NBC finally got around to mentioning it, the network spent just 18 seconds on it (see the coverage chart below).

NewsBusters notes that the "content of the coverage is every bit as biased as the time difference," with the three networks immediately painting Trump as somehow responsible for Duke's endorsement, while utterly absolving Clinton for Mateen's endorsement:

“So, how did he get this prime spot?” ABC correspondent Cecilia Vega asked as she wrapped her coverage of the incident, “Secret service telling us Mateen passed through metal detectors like everyone else. Clinton's aides will only say, ‘This individual wasn't invited as a guest and the campaign was unaware of his attendance until after the event.’”

CBS Evening News anchor Scott Pelley was even more dismissive of this incident, spending a brief 24 seconds on the topic before moving on to hype “divisions in the GOP,” “Clinton opened a rally near Orlando yesterday by paying tribute to the 49 people who were murdered in June at the pulse nightclub. Well, it turns out just a few feet away, wearing a red hat, was Seddique Mateen, the father of the Orlando gunman. Today, the Clinton campaign said Mateen was not invited to the event, the event was open to the public.”

Compare that to ABC anchor Tom Llamas describing Duke's endorsement as “the moment that’s jolted the Republican party.” Here's MRC's breakdown of the coverage by the big three:

More stories on Seddique Mateen.

More stories on David Duke.