First there were the MAGA-hat-wearing Covington Kids who were accused of surrounding a native American elder and mocking him. Then Jussie Smollett claimed that two Trump supporters beat him, put a noose around his neck and poured bleach on him. Both turned out to be hoaxes but not until they had gotten sustained national attention. There have been numerous other, similar hoax crimes - hate crimes that turned out to be hoaxes. The purpose of the majority of these hoxes is to discredit Trump voters.
These always play out the same way, First someone announces that a hate crime was committed and that it was inspired by President Trump. People who hate Trump spread the word and point to this as an example of how the President empowers hate crimes. Then, when it comes out as a hoax, Trump-haters complain that it distracts from actual hate crimes which are increasing.
What never, ever happens is Trump-haters reevaluating why they were so ready to believe so many false claims. Instead, each false claim seems to reinforce their belief in violent, hateful Trump supporters. A few, such as an editor for the Washington Post, have come out and said that they need such crime to be true and that they would prefer that then to know that Trump supporters are not roaming wealthy sections of Chicago in sub-freezing temperatures looking for black gays to attack.
They need incidents like this as a way of bludgeoning Trump supporters. "You see?" they say, "You are associated with terrible people. If you don't repent then you are complicit in everything done in Trump's name." Even hoaxes are somehow evidence of Trump's malign influence.
All of this has a cumulative effect. After the two widely-publicized MAGA incidents this year people have proclaimed that the red MAGA cap is the new Klan hood. And no one announced that MAGA caps are OK after all when the crimes turned out to be hoaxes. There's also danger in this. At least a few real hate crimes have been perpetrated against people in MAGA caps and conservatives in general. A clerk in a store shouted at a 14-year old because of his MAGA cap, someone else actually pointed a gun at someone because of his MAGA cap and someone at a Turning Points USA table at a college was punched in the face for spreading hate. These incidents are barely publicized, even though all of them are worse than what the college kids were accused of doing. And all have been confirmed by police reports or unedited video.
It also has the effect of dividing the country further politically. We are currently at the point where the Democrats are basing their positions on opposing President Trump rather than on what's best for the nation.
I should mention that real hate crimes do exist and the number of reported incidents is up. This does not mean that hate crimes are up. The number of bodies reporting has increased and it's entirely possible that people are quicker to take offense and report an incident as a hate crime. Also, and this is really important, the largest increase by capita is hate crimes against Jews. It's likely that a large portion of this is coming from the left instead of from the right. The New York Times has reported that in the last 22 months, none of the antisemitic acts in NYC have been traced to anyone associated with right-wing politics.