There is plenty of evidence that his family and campaign workers had an astounding number of suspicious contacts with Russians, some of which were almost certainly illegal.
Plus, Trump, his family, and his inner circle have repeatedly lied about contacts with Russians, publicly, in sworn testimony in front of Congress, and on security clearance forms. They have had numerous financial dealings with Russians, including criminals and oligarchs that were lied about.
Trump has refused to implement the sanctions against Russia that he signed into law and that were supposed to start on October 1.
Trump and his gang's behavior sure looks like guilt and fear of exposure. The blind gullibility of their supporters in the face of the largest criminal enterprise ever pulled off in America is what I find astounding.
What if Eleanor Roosevelt had wings? -- Monty Python
One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie
If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy
The reason that we have the scientific method is because common sense isn't reliable. -- Taq