"Obama is an [expletive,]" the New York Daily News quoted him as saying in a video posted on TMZ. "Unless you're interested in never having any money and being socialized."
The 69-year-old musician went on to say if Obama is re-elected this fall, "you're [expletive.]"
He also had no kind words for presumptive Republican presidential candidate Mitt Romney, the Daily News reported.
"Our guy isn't any good," Johnston said.
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