Obama: Black Lives Matter activists can't 'keep on yelling'

LONDON, England -- President Barack Obama is offering some advice to young activists: Be realistic, and be ready to compromise.

Obama says marriage equality advocates were effective in persuading him to shift his stance on gay marriage. He credits the movement, as well as his two daughters, with convincing him and others that the issue wasn't just a legal matter, but about a "sense of stigma."

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He says that's something he should have understood earlier.

Obama didn't shower the same praise on the Black Lives Matter campaign. He says the criminal justice and racial equality activists have been "really effective in bringing attention to a problem." But he warned that when politicians are ready to address a problem, activists have to be ready to present a realistic agenda.

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He says, "You can't just keep on yelling at them. You can't refuse to meet because that might compromise the purity of your position."

Obama says advocates must be prepared to negotiate and "occasionally take half a loaf."

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