Democrats have settled on a strategy for the midterms, hitting the Republicans for fostering a “culture of corruption.” It’s an easy argument to make, given the number of Donald Trump advisers and administration officials who have had to resign, been indicted or convicted — and that’s not counting the scandals that have ensnared some of Trump’s earliest supporters in Congress.

Will this message resonate with voters? The historical record offers plenty of evidence that it could succeed, so long as Democrats keep the focus on the larger Republican Party rather than on Trump alone.

The idea of making corruption an issue hasn’t always been a winning strategy. In the 19th-century United States, most corruption was usually entangled with the petty graft, bribes and kickbacks associated with local machine politics in the nation’s fast-growing cities.

This kind of corruption, though, didn’t just enrich a handful of well-connected pols and their wealthy backers. Instead, machine politicians instilled loyalty among their ward bosses, captains and constituents by distributing patronage jobs, government contracts, bribes and other enticements.

Though such ill-gotten gains may not have been allocated fairly, these quid pro quo relationships insured that they didn’t just benefit, say, one congressman and his pet rabbit. As a consequence, voters didn’t rush to punish corrupt politicians. They had too much to gain from the corruption endemic to machine politics.

Corruption at the highest levels of government did not lead to significant electoral consequences, either, though for very different reasons. The administration of Ulysses S. Grant, for example, became embroiled in numerous scandals. But did voters punish the Republican Party? Not really: Republican losses in the midterm elections of 1874 had far more to do with Democrats’ growing ability to suppress the black Republican vote in the Reconstruction South.

It helped, too, that voters rarely made national scandals a factor in how they voted for their local representatives. In the 20th century, though, this began to change, driven by the nationalization of politics.

Previously, it was hard to view an entire party as guilty of corruption, but the creation of national media markets and a centralization of political power in Washington helped make this charge increasingly viable. At the very same time, the decline of machine politics stripped corruption of its positive associations.

These related changes made politicians charged with corruption more vulnerable to vengeful voters. Two scholars who have studied the issue found that from the 1930s onward, corruption increasingly involved “mostly random acts of narrowly self-interested officials who return nothing to the public.” Voters formerly happy to tolerate corruption because they formerly got a piece of the pie now began to punish bad behavior at the ballot box.

Indeed, several studies of 20th-century politics have shown that candidates suffer when charged with corruption. In general, this research has demonstrated that incumbents accused of corruption tend to see significant reductions in their expected vote tallies: anywhere from 5 percent to 15 percent, depending on the severity of the charges.

But these punishments are meted out on the individual level. Can corruption charges stick to an entire party? History suggests that it can, though here the evidence is a bit more spotty and inconclusive.

The textbook case, perhaps, are the 1974 midterm elections, when Richard Nixon’s scandals and ignominious resignation — followed by President Gerald Ford’s controversial pardon — helped fuel a powerful backlash against the Republican Party. In those elections, Democrats toppled 49 Republicans in the House of Representatives, giving them a supermajority; they also posted significant advances in the Senate, too. But these gains proved fleeting in the following years.

During Bill Clinton’s first term, Republicans repaid the favor. They took a corruption scandal that actually involved both parties — the check-kiting controversy known as Rubbergate — and managed to direct most public anger at the Democrats. This, combined with other issues like the health care reform debacle, enabled Republicans to sweep the Democrats from the House and Senate while simultaneously capturing a majority of governorships in fall 1994.

The Republicans pulled off this feat by nationalizing the election, making the many local races an opportunity to send a much larger message.

In 2006, it was the Democrats’ turn. Democrats made an issue of payments and gifts that lobbyist Jack Abramoff showered on members of Congress. Abramoff’s largesse became synonymous with corruption, and because Abramoff was most generous to Republicans, Democrats took the issue and pinned it squarely on the opposition party.

The strategy worked. Even though many Republican members of Congress never accepted payments from Abramoff, the public came to believe otherwise: A poll conducted early in 2006 revealed that only 11 percent of Americans believed that the Abramoff bribes were “isolated incidents of corruption.” More to the point, 31 percent of Americans believed Republicans were “more involved in corruption and bribery in Congress,” while only 14 percent of respondents characterized Democrats this way.

In November that year, the Democrats managed to capture the House and Senate as well as a majority of governorships and state legislatures.

Which brings us to now. Recently, a GOP operative told a reporter that the Republican Party increasingly resembled a “criminal enterprise” — a frank admission, perhaps, but one that is increasingly hard to dispute in the court of public opinion. While Trump and his base will remain immune to arguments about a “culture of corruption,” history suggests that the rest of the electorate may find the message compelling.

But Democrats may not want to push matters too far. Back in 1998, Newt Gingrich and other congressional Republicans tried to make the midterms a referendum on President Clinton’s scandals. So far, so good. But they made it clear to voters that if they regained control of Congress, Republicans would impeach the president.

Voters didn’t like the sound of promised retribution. That year, Democrats unexpectedly gained seats in the House of Representatives. A political party hadn’t pulled off this feat in the sixth year of a president’s term for, well, almost forever: 176 years to be exact, back in the administration of James Monroe.

A word of advice to the Democrats: Target the party, not the president.

Stephen Mihm is an associate professor of history at the University of Georgia.