Marcy Wheeler provides a very detailed, somewhat technical roundup of the evidence:
At a minimum, to blame Russia for tampering with the election, you need high degree of confidence that GRU hacked the DNC (item 2), and shared those documents via some means with Wikileaks (item 8). What is new about Friday’s story is that, after months of not knowing how the hacked documents got from Russian hackers to Wikileaks, CIA now appears to know that people close to the Russian government transferred the documents (item 8). In addition, CIA now appears confident that all this happened to help Trump win the presidency (item 13).On Twitter (I've become a Twitter junkie for the first time ever), Grudge (@grudging1) lists everything that he/she can think of that ties Trump to the Russians, beginning here:
1. Let me see if I can try & remember all the blatant Russia/Trump things are out there— Grudge (@grudging1) December 10, 2016
I'm not going to editorialize much here; it's safe to say that I was in the Obama camp of being pretty sure (in his case, it seems he outright knew) that Russia was trying to manipulate the election in Trump's favor but that I didn't think it would be worth bringing up more than Clinton and her people did because I didn't think he had a chance of winning (and if I'm kicking myself now, I can't imagine how Obama will ever forgive himself).
Ultimately it is the President, invested with the powers as Commander-in-Chief, who could have chosen to act aggressively against Moscow. But he wanted to present a unified front across the American political spectrum. He wanted bipartisan support—and when McConnell rebuffed this effort (more on that in a bit), the White House decided to take the cautious route to “name and shame” the Russians.
This was, to put it mildly, an ineffective strategy.
The White House should have pulled out all the stops to halt this obvious threat to the electoral process, and let the political chips fall where they may. Obama is well aware of the GOP’s massive resistance strategy against his policies—just ask Merrick Garland—but this serious challenge to our civilization should have stiffened this President’s resolve. But it didn’t.
Obama could have retaliated brutally, clandestinely, mercilessly, creatively, painfully, unilaterally—but he didn’t.
Ultimately, a mild reaction was Obama’s decision; a poor decision. But it was his decision.
It all adds up to Trump's illegitimacy, according to Justin Rosario:
The time for debate is over. Donald Trump's "win" is not legitimate by any definition and every position he fills, law he signs or executive order he pens must be considered an illegal power grab by the Republican Party.
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Legitimizing the slow moving coup Republicans are on the verge of pulling off means the end of the American Experiment. We allowed our election to be stolen by a foreign power and the greedy Republicans enabled it with no thought to the cost. The Democratic Party is all that stands between the world and a super power now turned rogue nation. If they can't fight back, we're facing a new Dark Ages we may not recover from.
I still see only one solution to pursue. Say it with me: #LockThemUpandRunItBack