On Thursday, he used Twitter to vent about something that frustrated him: Hillary Clinton's assertion that she leads the Democratic primary by 3 million votes, a figure that he says is inaccurate and overstated.
Here were King's tweets on the subject.
"First, I have to expose a HUGE lie that is being told by @HillaryClinton and her team. She DOES NOT have a 3 million vote lead," he tweeted. "Did you know that in Hillary's '3 million vote lead' that many states where @BernieSanders won BIG, like Washington state, aren't included? Washington State has 7.2 million people. @BernieSanders won 71% of the votes. NONE of those votes count in the 'popular vote totals'. In fact, 12 of the 21 contests won by @BernieSanders were caucuses and their actual vote totals are NOT included in 'popular vote' tallies. For instance, @BernieSanders won 81% in Alaska. Not a single of those votes are included in the popular vote tallies. Not only that, but in the 15 caucus states, they don't function by popular vote totals. So ANY statement on who won the popular vote is OFF."
The idea that the popular vote totals are flawed because caucuses aren't included has been floating around for a while. The point of questioning the sum is obvious: To question the extent to which Democratic voters (and independents voting in Democratic contests, who usually favor Sanders) have preferred Clinton as the party's nominee.
This has been floating around so long, in fact, The Post's fact-checkers looked at this issue at the beginning of April. Did Clinton at that point actually lead by 2.5 million votes, as she claimed? No, she didn't.
She led by 2.4 million votes.
The Post's Glenn Kessler arrived at that figure by taking estimates of how many people came out to vote in caucus contests and applying the final vote margin to that population. This is admittedly imprecise, as King notes, since in some caucuses (like Iowa's) voter preferences can and do change. Kessler's total included Washington, despite King's insistence — and in Washington, he figured that Sanders had the support of 167,201 voters to Clinton's 62,330. Despite that, still a 2.4 million advantage for Clinton.
It's worth noting that caucuses, for which it's harder to calculate vote totals, are usually in smaller states and/or have smaller turnout. King's concern about ensuring Alaska's huge Democratic voting base is included in the tally is answered by Kessler's math.
What's more, Kessler continued updating his tally as results came in. The most recent update was after the contests on April 27, at which point Clinton's wins in New York, Pennsylvania, Maryland and other Northeastern states had extended her lead to "just over 3 million votes" — including his estimates for the caucuses. (By my tabulation of Kessler's numbers, it's 3.03 million.)
Since then, there have been five contests.
In total, then, Clinton's lead over Sanders in the popular vote is 2.9 million. The difference isn't because the total excludes Washington. It's because it includes more recent contests from the past 14 days.
That number will continue to change. There are only two big states left — New Jersey and California — both of which vote June 7. Clinton leads by a wide margin in New Jersey, where more than a million people turned out in 2008. She has a smaller lead in California, where about 5 million voted in the Democratic primary eight years ago. For Sanders to pass Clinton in the popular vote, he would need turnout like 2008 in California — and to win by 57 points.
What's very much worth adding to this conversation is that in 2008, Clinton won the popular vote, too, if you include the weirdness in Michigan. That year, though, Barack Obama lead in pledged delegates, as Clinton does now, and managed to woo superdelegates as a result of leading in the pledged delegate count.
King goes on to address superdelegates in his tweets, too, arguing that Sanders's stronger performance against Donald Trump in polling should spur superdelegates to anoint Sanders at the convention.
Sure. But a better measure of who voters prefer to have as the nominee is letting them vote on it. And so far, 2.9 million more of them have picked Clinton.