The United States is a country that's long been held to high standards. Immigrants immigrate here because they believe it's the world's best country, where politicians are free from corruption and the president has the highest level of integrity possible.
Trump has created a divisive, hostile environment for both politicians and ordinary citizens. It's a shame to know that so many far-right extremists are still out there and will continue to be emboldened by him after his presidency. They feel emboldened to create and spread lies as they see fit. When things don't go their way or fit their narrative, they feel like it's normal and acceptable to start believing in lies and spreading these lies.
I feel sorry for the many immigrants who had to witness this. I know many of them supported Trump, but it's likely they just didn't know any better.