Apparently, the only person who really didn’t know which party’s caucus Angus King would join in the U.S. Senate may have been Maine’s new senator-elect himself.

While it seemed obvious to both supporters and opponents that King, an independent, would sit down with the Democrats when it came time to vote for leadership, King always said he was still struggling with the question.

On Wednesday, King finally announced that he would caucus with the Democrats. And while that conclusion surprised few, how he says he reached it may tell us something.

All during the campaign, King said he was not sure which party he would join for organizational purposes, but few believed it.

Republicans didn’t believe it, and called King a closet Democrat. The national Democratic Party didn’t believe it, and abandoned its own nominee to stay out of King’s way.

But as King walked through his thought process on Wednesday, it didn’t sound as though he had just been playing coy all along.

King repeated that he would have preferred to operate without a party, joining different coalitions on different issues, depending on how he felt Maine’s best interests were best served. But that would not be practical, King said, because it would not give him an assignment to a committee, where most of a legislator’s important work gets done.

And, in a telling moment, King said the fact that the Democrats kept their majority made his decision easy. In a partisan body like the U.S. Senate, there is little incentive to join the minority. In the rare instances when senators and members of Congress change parties, it is almost always to join the majority party.

Had the Republicans taken control of the Senate this year, it is not difficult to imagine King joining them. During his eight years as governor, King was nothing if not pragmatic, and there would be very little advantage gained for him or his state from teaming up with the election’s losers.

Now, he says he is joining the Democrats not because of his historical connection to the party, but because it’s the pragmatic move. Had a few close Senate races gone the other way, King may well have been announcing his plan to caucus with the majority Republicans. So when he said he didn’t know which party he would caucus with, he meant it.

There may not have been much suspense about King’s announcement, but as a window into how he will make decisions, it has been instructive.