Democratic presidential candidate Kamala Harris on Monday planned to reemphasize her message that Donald Trump would endanger U.S. democracy if he regains the White House, drawing material from her Republican opponent's rallies and his recent ominous statements about "the enemy from within."

Harris was planning to show clips of Trump's rallies at her own rally on Monday in Erie, Pennsylvania, according to a senior campaign official who spoke on condition of anonymity, to try to make the point that Trump poses a danger because he believes those who do not agree with him are an enemy.

Trump in recent rally speeches has hinted darkly about facing "an enemy from within," more dangerous than a foreign adversary.