Mueller testified that he could not rule it out.
But any impeachment process would fail unless at least 20 republican senators support it, since it needs a 2/3 vote to pass.
Until republicans wise up and finally admit that Trump is a stain, there is not much that can be done.
But in 2020, when the orange disgrace is voted out, I am sure some people will begin talking because they would no longer fear the fat imbecile, and would not want to risk sinking with him.
Then it will be proven, and Trump will be sent to rot in jail, where he belongs.