The special election in the 18th congressional district of Pennsylvania this week will have mirror opposite effects on the two parties.

Democrats, enthused by victory in a district that voted for Donald Trump by almost 20 points in 2016, will contribute more money and time to Democratic candidates. Republicans, alarmed by a potentially disastrous cascade — loss of control of the House followed by two years of public hearings into Trump’s malfeasance followed by more electoral trouble — will call on corporate benefactors and wealthy donors to increase funding to stave off defeat.

Former Republican Representative Tom DeLay, the onetime golden arch extending from K Street to the conservative movement’s operational base in the GOP House, once complained that “Americans spend more money on potato chips than they do on all political races put together.” As the partisan struggle for political, cultural and legal supremacy grows ever more bitter, political spending is ratcheting up.

For Republicans, the results in Pennsylvania are unspinnable: The chips are down. Democrat Conor Lamb improved on Hillary Clinton’s performance in the district among both non-college-educated whites and more affluent suburban whites. Republicans, carrying the weight of Trump’s unfitness, tried multiple messages. “It means that nothing is working for them — not the tax bill, not tariffs, not Trump rallying his so-called base, and not their attacks on Pelosi,” said Democratic pollster Geoff Garin in an email.

According to Bloomberg Government, $17.5 million had been spent in the district by election eve. The Democrat Lamb out-raised the Republican Rick Saccone among individual campaign donors by around 4-to-1 — a measure of Democratic intensity. Republicans countered by spending more than $10 million via outside groups, including the National Rifle Association, for a 10-to-1 advantage in independent spending.

Not all spending is equal, however. On television, candidates are given the lowest rate for advertising. Outside groups are not. As the airwaves grow more cluttered with ads, it can cost twice as much, even more, to air an ad financed by an outside organization as one funded by a candidate.

Consequently, at least on television, Lamb’s money bought more than the money provided by Republican groups. That imbalance seems likely to play out in multiple districts this fall, with Democrats drawing more funds from small donors and Republicans relying more on interest groups.

The Pennsylvania special election did not hit the heights of absurdity reached by the special election in 2017 in Georgia’s sixth congressional district, outside Atlanta, where neophyte Democrat Jon Ossoff spent a truly ridiculous $29 million in a losing effort. That congressional race, the most expensive in history, burned up $60 million all told.

But spending $17.5 million on a House race outside Pittsburgh — the final tally will no doubt be higher — is crazy enough, especially given that television ad rates in Pittsburgh are about one-fourth of what they cost in Atlanta.

No one, not even the surest loser, turns away contributions. “There’s always an incentive to keep going,” said GOP strategist Mike Murphy in a telephone interview. “You get your first bad poll back, and you say, ‘Well, maybe we can turn this around by running our new Dancing Bear ad.’ And so you pile a bunch of money into your Dancing Bear ad. Nobody’s saying, ‘Spend less money.’”

When money flows freely, campaigns avoid difficult either-or tactical decisions. Instead, they opt for all of the above. “It gets to be overkill at some point,” emailed pollster Paul Maslin, who advised the amply funded 2017 campaign of Democratic Senator Doug Jones of Alabama. “But Alabama for us wasn’t all that different, and, believe me, we were glad to have every extra million we did — social media, radio, African American turnout, mail, as well as normal broadcast and cable TV.”

Jones spent more than $20 million last fall in his special election victory over Republican Roy Moore. The previous three Democratic Senate nominees for that seat, who had no hope of victory, spent $4,500 (2014), $333,000 (2008) and $1 million (2002).