It's not "just not agreeing with him or his opinion", it's statements that Trump has said that are factually untrue. Here are just a couple of examples from the debate. He said that his tax cut was the largest in US history - false. The Committee for a Responsible Budget says Trump's tax cut was only the 8th largest in US history. Trump said in the debate he authorized Pelosi the authority to call in 10K national guardsman on Jan 6th - not true. According to his then Sec of Defense, Chris Miller, testifying under oath to the Jan 6th Select Committee, he said Trump did not give Pelosi any such authority. These are but two examples of the many lies that Trump spewed during last Thursday's debate all of which can be factually debunked.