William Hung Backs Clarkson and Hudson, They Didn't Betray 'Idol'

William Hung doesn't think Jennifer Hudson and Kelly Clarkson betrayed "American Idol" by joining its arch rival, "The Voice" ... and even has a (long shot) plan B for producers.

Hung, who's a professional public speaker now, tells us he doesn't begrudge J-Hud and Kelly's decision to jump ship because it's been so long since they were 'Idol' contestants. Even though they, along with Hung, appeared on the big series finale last year on FOX.

It's been 13 years since his horrific rendition of "She Bangs" was banging around your head nonstop -- but Hung still has a big dream ... where 'Idol' is concerned.