If you include all ad time reserved in battleground states through Election Day, the advantage is … $140 million to zero.

I’ve been careful to note in poll posts lately that Trump’s numbers in the battleground states are more encouraging than his national polling (errrr, until today), which is good since national polls are ultimately meaningless. The not-so-small caveat is that, apart from the occasional rally or speech, he’s not competing in battleground states right now. Hillary has the field to herself. The glass-half-full spin on that is that it shows how much room Trump has to grow once his fundraising gets going and he starts buying airtime of his own. He’s within a few points despite barely having a functioning campaign! The glass-half-empty spin is that Team Clinton is seizing this opportunity to turn undecideds against Trump with no resistance apart from whatever free airtime his team can get from cable news networks.

Obama’s campaign alumni have said in the past that they thought the first few months of the race against Romney in 2012 were key in defining him as an out-of-touch plutocratic stiff. What we’re seeing right now is a de facto controlled experiment testing that theory. If one candidate spends a bunch of money early and the other candidate spends literally nothing, what effect will that have on subsequent polling? Does it matter that everyone in America already knows who Donald Trump is and has formed some opinion about him?

The theory of Trump’s campaign is that he’s such a media stud that he doesn’t need the volume of ads that traditional candidates do. Author Lynn Vavreck, who studied the effect of ads in elections in several countries, says that assumption is risky:

The evidence suggests that campaign ads have small effects that decay rapidly — very rapidly — but just enough of the impact accumulates to make running more advertising than your opponent seem a necessity…

A study estimated that most of the impact of an ad in a presidential election is gone within a day or two of its airing (I am one of the authors of this paper). In governor, congressional and Senate elections, the effects last a bit longer: three or four days. Fleeting effects on campaigns have been shown by various authors in the lab; in Canada; in the 2000 and 2004 general elections; in the 2006 midterm elections; in the 2012 general election; and in field experiments in a Texas governor’s primary in 2006 and a general election in 2014.

The takeaway from these studies is simple: Even though the effects from an ad imbalance are small and go away fast, candidates cannot allow them to pile up. Election Day may be far away, but candidates may still want to match their opponents’ daily advertising in the months before the vote because they care about publicly released news polls that convey information to voters — and donors — about their viability and the closeness of the race.

Super PAC ads in the GOP primary did put a dent in Trump’s polling temporarily, notes Vavreck, but his numbers bounced back when he responded with ads of his own. The question is what happens when one candidate is making an argument at length via a string of ads with no rebuttal, as Hillary is doing presently in swing states. Does the impression of the target “harden” in voters’ minds so that it’s more difficult for him to undo that impression later? Consider too that Clinton will enjoy a financial advantage for the rest of the campaign. If her early ads form a damaging but reversible impression of Trump in voters’ minds, she may have the dough to reinforce that impression with an overwhelming amount of ad spending even after he’s on the air himself trying to reverse it. And of course, even apart from Clinton’s advantage, Trump is missing opportunities by not running ads right now. Yesterday’s speech on protectionism ideally would be sliced into several key soundbites and then put on the air in Pennsylvania and Ohio to amplify his message that Clinton is waging war on the working class. Instead he’ll have to hope people caught it on the news. Put it all together and he may be slowly sliding into a small but durable hole from which it’ll be hard to dig himself out.

Relatedly, left-leaning pollster PPP released some new battleground data yesterday. Unlike today’s Ballotpedia bloodbath, none of these numbers (except maybe Wisconsin) is daunting for Trump. But it’s worth noting that the last polls taken in Pennsylvania, Ohio, and New Hampshire all had the race closer than PPP does now.

He’s under 40 percent in half of those states. His best number, 44 percent in Arizona, comes in a state that’s supposed to be dependably red, not a battleground at all.

Look at it this way: He’s just one $150 million check to his campaign away from equalizing his ad arsenal with Hillary’s. Any day now. In lieu of an exit question, here’s a clever bit of overpromising by Team Trump designed to get its fans to reach for their wallets:

Um….WOW: Trump fundraising off promise to indict Clinton pic.twitter.com/3MpgsRwYIm

— Zeke Miller (@ZekeJMiller) June 28, 2016