OTTUMWA, Iowa — As excellent as the Bernie Sanders event was — as excellent as it was to hear from the filmmaker Michael Moore and to eat Ben & Jerry’s ice cream scooped by the actual Ben and the actual Jerry, longtime Sanders supporters — it would have been even more excellent, was the general feeling, if Mr. Sanders himself had been able to come to Ottumwa.

But Mr. Sanders was stranded in Washington, languishing at President Trump’s impeachment trial along with two other top contenders in the Iowa Democratic caucus, Senators Amy Klobuchar and Elizabeth Warren. And we — the voters, and the people who had traveled to Iowa to write about this very odd week at a very odd time in American politics — had to take what we could get.

“The caucuses are always weird,” said Philip Elliott, a Washington correspondent at Time magazine, “but the absence of three of the top candidates really messes with the schedule.”