You make a good point, in that evidence does not equal proof. There is lots’ of evidence now of collusion between Trumps team and the Russians. So what does that prove? It remains to be seen who maybe be indicted. We don’t know yet how high up this goes.
Another important point you allude to is that there can’t be a cover-up without a crime. Unfortunately that train may have already left the station. Aside from the FICA warrant to monitor Page, we also have Flynn and Giuliani asking for immunity, and Session’s ‘recusal’. So the failed attempts to halt the investigation, form Devin Nunes’ charade to Trump’s own admission to why he fired Comey will become compelling evidence once indictments are unsealed at any level.
A minor point. Depending how you measure it, Trump/Russia is already bigger than Watergate on many levels. Watergate was an internal spat, while Trump/Russia involves a long time international adversary. And while Watergate was a physical break-in involving thousands of documents, we now have a 21st century digital break-in involving millions of documents from both the DNC and RNC that threatens our Constitution. This is already the defining scandal of the Trump administration. One measure of Watergate is that there were 69 indictments and 49 convictions within the Nixon Administration. Let’s see how the Trump team measures up.
But back to my original point, so far the Congress and Senate have remained partisan. But as the public becomes aware of Trump Russia connections, and now the cover up, Republican’s may turn against Trump. The good thing about an impeachment under the current Congress is that it would be a non-partisan venture. With serious crimes like foreign interference in our election, the time has come to put country before party.