Andrew Breitbart's heart was too big to fail, but it did anyway. If you don't know who Breitbart was, you haven't been paying attention. A conservative activist, entrepreneur, author, muckraker, media pioneer and performance artist of sorts, in his heart he was a radical. His friends saw him as a fearless truth-teller and provocateur. (The word "fearless" will have to be retired from overuse when all of his obituaries have been written.) His enemies, and they are legion even in death, saw him as the most vile creature who ever slithered upon the earth. Within hours of the news,...