But what is the evidence that we know he (Putin) has over him (Trump)? Or if we don't know what, what is the evidence that we have that proves that he has something on Trump?
We have several possible what's, but nothing that has yet passed the test of being proved in a court of law.
But that there is something is proved simply by the latest summit in Helsinki. I put my understanding of the situation above, but the veneration Trump heaped on Putin, his insistence that no other Americans be present in his meeting with Putin, and his absolving Putin and his government of any interference in the 2016 election despite borad concurrence among the intelligence community, as well as the Senate, that there was Russian interference, all points to it.
I know of no other explanation that parsimoniously explains why Trump would do something that was so politically risky back home, for absolutely no gain. Putin conceded nothing, Trump fawned over him and said he didn't do anything wrong. If you have alternative explanations, I'm interested to hear it.
And this ignores all the other stuff, of course, which indicates some level of cooperation between the Trump campaign and Russia. The Trump Jr. meeting with the Russian lawyer offering dirt on Clinton, which is on the record, and happened beyond a shadow of a doubt. Jared Kushner wanting a way of communicating with the Russians that American intelligence wouldn't be able to hear into.
It is based on facts: That he 1) Boasted about grabbing women by their genitals; 2) Refused to condemn neo-Nazis in Charlottesville; 3)Continues to profit from the Trump organization, from which he has refused to clearly divest his interests, and which continues to reap slef-dealt campaign and foreign money.
And that's just a small sampling of his many failings. These are facts my opinion is based on.