No, the liberal agenda doesn't "support those videos," and it doesn't support the activity in them. However, their agenda to create class and racial division needs to be based on the idea that whites are the colonizing boogeymen, out to prey on women and minorities. That means that if the demographics in this video are reversed, it would be flooding the proverbial airwaves and making national news, with every race hustler, liberal scumbag politician, and celebrity racing to the first twitter feed or microphone they can find to decry this awful incident as more evidence of a rise of Trump-related racist emboldenment.
Instead, videos and incidents like these are outright ignored in this country every single day, because they don't benefit the agenda.