“After spending a billion dollars on his own candidacy in the primary, many in the party thought that would imply spending at least as much on the general election, if not more,” said Eleanor Neff Powell, an associate professor at the University of Wisconsin-Madison with a focus on money in politics. “A billion dollars may be an unreasonable expectation, but he set — and in some ways expanded — those expectations during the primary, even if he didn’t outright say how much he planned to spend in the general.”