At the private air terminal at Logan Airport in Boston early Wednesday, men in unwrinkled suits sank into plush leather chairs as they waited to board Gulfstream jets, trading consolations over Mitt Romney’s loss the day before.

“All I can say is the American people have spoken,” said Kenneth Langone, co-founder of Home Depot and one of Mr. Romney’s top fund-raisers, briskly plucking off his hat and settling into a couch.

The biggest single donor in political history, the casino billionaire Sheldon Adelson, mingled with other Romney backers at a postelection breakfast, fresh off a large gamble gone bad. Of the eight candidates he supported with tens of millions of dollars in contributions to “super PACs,” none were victorious on Tuesday.

And as calls came in on Wednesday from some of the donors who had poured more than $300 million into the pair of big-spending outside groups founded in part by Karl Rove — perhaps the leading political entrepreneur of the super PAC era — he offered them a grim upside: without us, the race would not have been as close as it was.