He appeared on stage, during the election, and cheerled a series of email hacks conducted by the Russian government that almost certainly determined the outcome of the election. I accepted the results of the election at pretty much the same time Clinton did, the day after election day, but the accusation is colorable. Unlike birtherism. And no, the latter is not an amplified version of the former!

It’s a huge leap to go from cheering the leak of those emails to alleging that Trump colluded with Russia to “steal” the election. To me that implies manipulating votes. I don’t think releasing information can ever count as “stealing” an election. Certainly that doesn’t justify calling him “illegitimate.” If those emails changed the outcome of the election, that’s only because the information was probative to voters.

To use a legal analogy, I don’t see political discourse as being something where there should be judges excluding unreliable or prejudicial materials. Information is fair game.

If true, isn't it essentially a recapitulation of Watergate, except that the break-in occurred online and not in a DC hotel? Watergate cost Nixon his presidency.

I was against impeachment (I still think it was stupid), because it was a political stunt with no hope of actually removing the president. But just morally, Trump richly deserved investigation. "Where's there's smoke, there's fire", and Trump's campaign and administration put out a burning oil well's worth of smoke. He lost his National Security Advisor to a foreign agent violation within weeks of taking over. Senior members of his campaign coordinated with Julian Assange. I don't think you can pretend like this was all fake.

(Just to calibrate: I also think Clinton should have been impeached).

There was an uncharted level of animosity in public discourse that election cycle mostly because of Trump, and within the context of all the shit-flinging happening at that time of "locking her up", this accusation being made by a politician on a morning show, while I agree with you it's not entirely going along the spirit of a peaceful transition of power, I rather chalk it up as just a punch back in the political arena. Yes, that she said this was not responsible on her part, but she did call Trump a day or two after the election to concede and congratulate him on his win.