Errol Louis is the host of "Inside City Hall," a nightly political show on NY1, a New York all-news channel. The opinions expressed in this commentary are his own. View more opinion articles on CNN.

(CNN) It took hours for the White House to issue a condemnation of the disgusting video obtained by the New York Times that depicts President Trump violently slaughtering journalists and political opponents (including former President Obama and sitting members of Congress). The footage, created from a grisly scene in a Hollywood movie, was shown at a meeting of the pro-Trump political group, American Priority, at the Trump Doral resort.

Errol Louis

If history is any guide, Trump's supporters will concoct excuses or even pass the video off as a joke.

White House press secretary Stephanie Grisham said that Trump had not yet watched the video, and added that "based on everything [Trump] has heard, he strongly condemns this video." Tim Murtaugh, a spokesman for Trump's campaign, told the Times "That video was not produced by the campaign, and we do not condone violence."

But the damage is already done: the Trump movement has pushed America another step closer to the dangerous idea that violence is part of politics as usual.

From the early days of Trump's campaign for President, the candidate and his followers have openly encouraged political violence. In some cases, his supporters have committed it. In November of 2015, activist named Mercutio Southall was cursed, punched and beaten at a Trump rally as the candidate shouted, "Get him the hell out of here!"