Sherrod Brown: A Big Lie

Extreme left wing Ohio Senator Sherrod Brown is running an ad that accuses his opponent of telling "The Big Lie." Why does Love & Compassion disappear when there's a tough race?

The Big Lie is a propaganda technique. The expression was coined by Adolf Hitler, when he dictated his 1925 book Mein Kampf, about the use of a lie so "colossal" that no one would believe that someone "could have the impudence to distort the truth so infamously." Hitler asserted the technique was used by Jews to unfairly blame Germany's loss in World War I on German Army officer Erich Ludendorff.

That's Wikipedia's explanation of The Big Lie. So how does Brown justify his actions?