They're trying to make a case that Trump was trying to overthrow the government and are referencing things he said to make their case, ie on such and such dates he tweeted this and called that person and yada yada, this is a circus show compared to actual professional trials where there have to be actual steps taken towards an effort not just someone whining on social media and bitching on phone calls, Trump himself is a joke but this isn't really about him, it's about normalizing the idea that all a person has to do is openly criticize and question the government while demanding investigations & that alone being enough to convict someone of conspiring to overthrow the government, it's just another step towards overt fascism