No US president can stay in power (avoid impeachment) if they are compromised by a foreign power.
“The Mueller Report reveals that, in the weeks before the 2016 election, Trump believed Kremlin agents held videos of him from a 2013 Moscow trip that could end his candidacy.
That Trump and his fixer Michael Cohen discussed these tapes suggests that they believe - as did the Kremlin agent they were dealing with - that they existed, and that the Kremlin was (through an intermediary) reassuring Trump that the Kremlin agent-held tapes would be suppressed.
The primary ground under which a POTUS could be impeached for an inability to uphold his Oath of Office and secure the national defense - that isn't criminal - is if he has been compromised by a foreign power via blackmail that provably puts him in thrall to a foreign power.
Mueller only put ‘high confidence’ intel in his report, so we know that US law enforcement holds that the Kremlin agent was telling the truth about the videos. And no US president can stay in power (avoid impeachment) if they are compromised by a foreign power. So impeachment is mandated for Trump.”
The full article is available here