The latest test of the "independent fact-checkers" just unfolded in a Joe Biden interview with Peter Doocy of Fox News in Dubuque, Iowa. It's cut, and dried. Biden is on record opposing Obama's decision to take out Osama bin Laden in 2011. But now he's claiming he never did. It's an easy "Pants on Fire" for PolitiFact. It's Four Pinocchios for The Washington Post.

PETER DOOCY: If you were ever handed a piece of intelligence that said you can stop an imminent attack on Americans but you have to use an airstrike to take out a terror leader, would you pull the trigger? JOE BIDEN: Well, we did. Guy’s name was Osama bin Laden. REPORTER: Didn’t you tell President Obama not to go after bin Laden? BIDEN: No, I didn’t. I didn’t.

Fox pointed out that's not what Biden said on video in 2012: "He said, ‘Joe, what do you think?’ And I said ...We owe the man a direct answer. 'Mr. President, my suggestion is, don’t go.’ We have to do two more things to see if he's there."

The Trump-Pence campaign is pointing out other evidence underlining Biden lied to Doocy.

-- When then-White House Press Secretary Jay Carney was asked whether Biden actually opposed the raid, Carney said, “I know that he’s speaking accurately.” (Carney was Biden's press secretary before he was Obama's.)

-- In a 2012 presidential debate with Mitt Romney, President Obama said Biden dissented: "When it comes to going after Osama bin Laden, you said, well, any president would make that call. But when you were a candidate in 2008 … you said we shouldn't move heaven and earth to get one man, and you said we should ask Pakistan for permission.And even some in my own party, including my current vice president, had the same critique as you did."

-- In each of their memoirs, former Obama officials Hillary Clinton, Leon Panetta, Robert Gates, and Michael Morell all say Biden opposed the raid.

It's one reason that Gates wrote in his 2014 memoir that Biden “has been wrong on nearly every major foreign policy and national security issue over the past four decades.” He told CBS he stood by that statement last May.