Let's review the brief exchange, which started at the 34:53 mark in the YouTube video of the full hearing, embedded at the end of this post:
McCain: So, really what you're talking about is if they succeeded in changing the results of an election, which none of us believes they were, that probably has to constitute an attack on the United States of America because of the effects if they had succeeded.
Clapper: We cannot say . . . they did not change any vote tallies or anything of that sort. (McCain talks over Clapper briefly.) We have no way of gauging the impact . . . on choices the electorate made. . . . Whether or not that constitutes an act of war is a very heavy policy call that the intelligence community can't make, but in my view, it's of great gravity.
Speaking of gravity, let's consider what is being discussed here. It's undoubtedly the single most important question hanging over the United States at the moment: Did Americans elect Donald Trump or did Russian hackers, at the direction of Vladimir Putin, manipulate vote totals to "select" Donald Trump? It was by far the key question to be addressed at yesterday's hearing, and yet exactly one minute from an almost 2 hour, 40 minute hearing was devoted to it.
Let's analyze what seems to be happening in the McCain/Clapper exchange:
* McCain asks a leading question, raising the notion of Russia succeeding at changing the results of the election, but adding, "None of us believes they were." That's the kind of sweeping generality that McCain cannot possibly prove and almost certainly is not accurate. But yet, it probably had an impact on Clapper's answer.
* Clapper starts to say something along the lines of, "We cannot say whether Russian hacks changed the election result." But then he catches himself and says, "They did not change any vote tallies or anything of that sort." Those are two very different statements, and Clapper clearly started out to say the former and changed course to say the latter.
Think of the many obvious questions that could have been asked as followups, by either McCain or someone else on the committee:
(1) Mr. Clapper, how do you know Russian hackers did not change the vote totals?
(2) Please describe, in detail, the investigative process that was used to reach this determination.
(3) What are the key technical findings that caused you to reach your conclusion? Have you even had time, less than two months, to fully investigate such a complex situation?
(4) Are you saying that Russia tried to change vote totals, but the U.S. thwarted them? If so, how did we thwart them? Did our firewalls and other protective devices work as they should have? Were our systems more secure than many press reports have led us to believe?
(5) What about the possibility of a hack on vote tabulations at the Associated Press, which reportedly had very poor cyber-security protocols in place. Did you check on that, and if so, what did you find?
(6) Going into the election, experts reported that Trump essentially had to win all of the following states -- Florida, North Carolina, Pennsylvania, Ohio, Michigan, and Wisconsin. He pulled off what seems to be an electoral miracle. What are the chances of that happening? Have you checked in each of those states to make sure vote manipulation did not occur?
(7) If Russia was involved in election interference, including hacking the DNC, why would they not go ahead and hack vote totals? I can think of only three reasons they wouldn't do it: (a) They were afraid to do it; (b) They did not have the capability to do it; (c) They had a sudden attack of conscience and decided it was improper to take their chicanery that far. Do you have reason to believe any of those three scenarios took place?
(8) Intercepts reportedly caught Russian officials celebrating and congratulating themselves after announcement of Trump's victory. Congratulating themselves for what? It sounds like they were congratulating themselves for some definitive steps they took to get Trump elected. Of all such possible steps, isn't the only one certain to work involve changing the vote totals? Just messing with the minds of American voters was not certain to succeed, was it? If not, then vote manipulation was required, correct? Even after all the pre-election mind games, polls showed Hillary Clinton winning fairly comfortably going into Election Day. Was vote manipulation the final arrow in the Russian quiver to make sure Donald Trump became president?
I could come up with many more similar questions . . . but, you get the idea -- and I'm just one guy with a blog from Alabama. Perhaps it will be proven that Russian did not manipulate the vote. But right now, evidence suggests U.S. officialdom has made no serious effort to find out.