"Why are you all assuming that US citizens are the leaker? It could also be 'leakage' via Russian cyber means. It's looked to me for several weeks like Vladimir was outing his puppet."

Good point, I'm of the opinion that Putin is blackmailing his puppet, hence all the fawning, sycophantic behavior on Twit's part. With this new sanctions bill being overwhelming passed in both the House and Senate, that he's said he'll sign, you wonder if the Kremlin will punish him with more damaging leaks.
At the same time though it does appear that the White House is leaking like a sieve from numerous sources.