Lawmakers and presidential candidates swiftly responded to Sunday morning's shooting at a gay nightclub in Orlando — the worst mass shooting in American history.

While they were united in offering condolences to the victims and their communities, they disagreed on the shooter's motivation (which is still not definitively known) and potential solutions to prevent future mass shootings. President Obama spoke at the White House, said the attack was an "act of terror and an act of hate" and again stressed a need for stricter restrictions access to guns. Donald Trump, the GOP's presumptive nominee, called for strengthening the fight against "radical Islamic terrorism" and for President Obama to use that phrase publicly — Trump tweeted that the president should "immediately resign in disgrace" if he does not.

Hillary Clinton echoed Obama's comments about the need for stricter gun control measures, also calling the shooting an act of "terror" and "hate."

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