(CBS News) For half a century, he took on corrupt politicians, scam artists and bureaucratic bumblers. His visits were preceded by the four dreaded words: Mike Wallace is here.
Wallace took to heart the old reporter's pledge to comfort the afflicted and afflict the comfortable. He characterized himself as "nosy and insistent."
So insistent, there were very few 20th century icons who didn't submit to a Mike Wallace interview. He lectured Vladimir Putin, the President of Russia, on corruption. He lectured Yassir Arafat on violence.
He asked the Ayatollah Khoumeini if he were crazy.
He traveled with Martin Luther King (whom Wallace called his hero). He grappled with Louis Farrakhan.
And he interviewed Malcolm X shortly before his assassination.
He was no stranger to the White House, interviewing his friends the Reagans . . . John F. Kennedy . . . Lyndon Johnson . . . Jimmy Carter. Even Eleanor Roosevelt.
Plus all those remarkable characters: Leonard Bernstein, Johnny Carson, Luciano Pavarotti, Janis Joplin, Tina Turner, Salvador Dali, Barbra Streisand. His take-no-prisoners style became so famous he even spoofed it with comedian Jack Benny.
It's hard to believe, but when Wallace was born in 1918 there wasn't even a radio in most American homes, much less a TV.
As a youth, Wallace said, he was "an overachiever. I worked pretty hard. Played a hell of a fiddle."
At the University of Michigan, where his parents hoped he'd become a doctor or lawyer, he got hooked instead on radio. And by 1941, Mike was the announcer on "The Green Hornet."
"My family didn't know what to make of it - an announcer?" he recalled.
He was soon the hardest-working announcer in broadcasting.
When television arrived in the 1950s, Wallace was everywhere . . . variety shows, game shows, dramas, commercials.
But it was an interview show called "Nightbeat," first broadcast in 1956, that Wallace remembered fit him like custom-made brass knuckles. "We decided to ask the irreverent question, the abrasive question, the who-gives-a-damn question."
Some, like labor leader Mike Quill, had never been spoken to that way. "Go ahead and ask your stupid questions," he retorted.
Neither had mobster Mickey Cohen, whom Wallace asked, "How many men have you killed, Mickey?"