WASHINGTON (AP) -- Marco Rubio says Republican front runner Donald Trump is "wrong" to refuse to condemn former KKK leader David Duke.

Trump was asked during CNN's "State of the Union" whether he publicly condemns "the racism of former KKK Grand Wizard David Duke," who was recently quoted equating voting against Trump to treason.

Trump replied he didn't "know anything about David Duke."

He added: "You're asking me a question that I'm supposed to be talking about people that I know nothing about."

Rubio said: "We cannot be a party who refuses to condemn white supremacists and the Ku Klux Klan."

He adds: "Not only is that wrong, it makes him unelectable."

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