One or two elections might decide whether Democrats or Republicans control the House of Representatives in 2019 — meaning it could all come down to a singularly bizarre forgery scandal ensnaring one GOP campaign.

In Virginia’s Second Congressional District, Republican Rep. Scott Taylor’s campaign is facing allegations that his staffers helped forge the signatures that gave an independent candidate the support she needed to get on the ballot in November. A judge decided to remove the independent candidate from the ballot because of the forgeries.

So the gambit didn’t work. But the Virginia story is far from the only Republican scandal that could tip the scales in the 2018 midterm elections.

In New York, Rep. Chris Collins has been indicted for insider trading. In California, Rep. Duncan Hunter is also facing charges for allegedly using his campaign’s cash to pay for a lavish personal lifestyle. In Iowa, Rep. Rod Blum is under investigation by the House Ethics Committee over his role in an internet company whose work is directly related to the federal government.

The scandals loom large this Election Day: The Cook Political Report has said all four races with implicated incumbent Republicans should now be more competitive for Democrats. Democrats hold a slight edge — but by no means a lock — on retaking the House. The peculiarities of each individual campaign and whether they swing any seat a little more toward one party matter a lot in the campaigns.

Democrats need to win 24 House seats to retake the chamber, and they already wanted to make corruption in Trump’s Washington a campaign theme. Four Republicans under investigation for various misuses of their office and campaigns could very well end up being the difference between a Republican and Democratic House.

The Scott Taylor voter signature forgery scandal, briefly explained

What’s the scandal? Taylor campaign staffers have been accused of submitting forged signatures for dozens of voters — including those of four dead people, as the Virginian-Pilot reported — to get independent candidate Shaun Brown on the ballot in November.

Brown, who ran against Taylor in 2016 as a Democrat, has said she didn’t know the Republican campaign had been collecting signatures on her behalf. The apparent goal of keeping her on the ballot would have been to split the Democratic vote between Brown and this year’s Democratic candidate, Elaine Luria. (Brown has her own legal troubles to worry about, as she is already under legal scrutiny for allegedly taking money from a school nutrition program targeted at low-income kids.)

According to the Virginian-Pilot, which attempted to contact hundreds of people whose signatures appeared on the forms to put Brown on the ballot, 59 people said that they had not signed the forms and therefore their signatures were fraudulent; several other signatures, including one of an 83-year-old man who died in 2016, were of deceased people.

Taylor has said he was aware that his staffers had been collecting signatures for Brown but claimed it was because they believe she had been “disenfranchised” by the Democratic Party.

A criminal investigation is ongoing.

What does the race look like? Taylor was always going to have a tough race against Luria, and the forgery scandal will only make it more difficult. The Cook Political Report moved the Virginia Second from Lean Republican to Toss-Up after Brown was taken off the ballot this week.

“Taylor is still a relatively undefined freshman, and the ‘dirty tricks’ that have dominated news of the race for the past few weeks could help Democrats chip away at his image as a squeaky-clean Navy SEAL,” Cook’s Dave Wasserman wrote.

Luria is a former US Navy commander who now runs an art studio. She has earned the Democratic Congressional Campaign Committee’s Red to Blue imprimatur, which means the national party thinks she’s shown she can be a credible candidate.

In 2016, though Taylor won handily, Trump beat Hillary Clinton in the Virginia Second by just 3 points. It’s a pretty diverse district too: 68 percent white, 20 percent black, 5 percent Asian, 5 percent Latino.

Taylor is an incumbent, but he is hardly an entrenched one. The New York Times and Siena polling found Luria trailing by just 3 points in mid-October.

The Chris Collins insider trading scandal, briefly explained

What’s the scandal? Collins was arrested by the FBI in early August, alongside his son and the father of his son’s fiancée on insider trading charges.

Collins was charged over his connection to the Australian biotech company Innate Immunotherapeutics. As the company’s largest shareholder, he allegedly shared private insider information with his son Cameron Collins, who then passed on information to his fiancee’s father, Stephen Zarsky. According to the indictment, inside knowledge of a failed drug trial allowed Zarsky to avoid nearly $800,000 in investment losses.

The federal indictment charges Collins, his son, and Zarsky with 13 counts of wire fraud, securities fraud, and making false statements to the FBI. Collins’s lawyers said the lawmaker would be “vindicated.” Collins, his son, and Zarsky all pleaded not guilty.

“Collins, who, by virtue of his office, helps write the laws of this country, acted as if the law did not apply to him,” US Attorney Geoffrey Berman said at a news conference.

While Berman made clear that this arrest is not related to Collins’s position as an elected official, his ties to this Australian biotech firm haven’t been just a family affair.

Last October, the Office of Congressional Ethics reported that it found “substantial reason to believe” Collins was using his position in Congress to personally benefit the company and solicit investors. GOP lawmakers told reporters that Collins has urged his colleagues to invest in the company on the House floor. A number of Republican members of Congress, including Texas Reps. John Culberson and Mike Conaway, are also investors in the company.

What does the race look like? At first, Collins suspended his reelection bid after his arrest.

“Democrats are laser-focused on taking back the House, electing Nancy Pelosi speaker, and then launching impeachment proceedings against President Trump,” Collins said in his announcement. “They would like nothing more than to elect an ‘Impeach Trump’ Democrat in this District, which is something that neither our country or my party can afford.”

But New York state election law dictated that Republicans couldn’t officially remove him from the ballot and name a replacement — so Collins reversed his decision and is running.

The Democratic candidate is Nathan McMurray, who is the Grand Island town supervisor. Before Collins’s arrest, McMurray hadn’t shown much prowess as a candidate — in fundraising or otherwise. But now as the only sure candidate on the ballot, he may have a chance.

The New York 27th is rated Likely Republican, after previously being Solid Republican, by Cook. According to the New York Times’s polling, Collins is only ahead by 4 points in a survey with a 4.8-point margin of error.

The Duncan Hunter campaign cash scandal, briefly explained

What’s the scandal? The FBI has been investigating Rep. Duncan Hunter (R-CA) and his wife, Margaret Hunter, for more than a year, with a grand jury questioning former aides, lobbyists, and family members. In late August, a 47-page indictment outlined a family that was spending beyond its means and illegally using campaign funds to support an expensive lifestyle.

“Throughout the relevant period, the Hunters spent substantially more than they earned,” the indictment reads, citing more than 1,000 bank overdraft fees in a seven-year time span and the family repeatedly maxing out credit cards. At the center of the indictment is Hunter’s wife, whom the lawmaker installed as his paid campaign manager because the family “needed the extra money,” the indictment states.

The misuse of campaign funds extends to the purchase of video games; more than $25,000 in family vacations to Italy, Hawaii, Las Vegas, London, and other destinations; more than $15,000 in airline tickets for the family, friends, and the pet rabbit; food and alcohol; holiday gifts; and more, concealing purchases as miscellaneous expenses or campaign activities or even reporting them as fraudulent. For example, the indictment reads:

The Hunters bought personal clothing at a golf course “so that the purchase could be falsely reported to the Treasurer as ‘balls for the wounded warriors.’”

The family would disguise purchasing video games by falsely telling their bank that the purchases were “fraudulent charges” — reporting that to the Federal Election Commission and the public.

Hunter and his wife used campaign funds to by items as small as “a ring pop” from Target, as well as Pittsburgh Steelers tickets, tickets to see the play How the Grinch Stole Christmas, and family groceries, which they would say were campaign-related.

Hunter’s office has chalked up some of these expenses as mistakes, and Hunter has maintained his innocence. According to a report in Politico from February, Hunter sold his home and moved his wife and kids to pay back some of the improper campaign fund uses. He, for the most part, lives in his Capitol Hill office.

Hunter has long been dogged by serious legal and ethics scandals. He’s known as the “vaping” Congress member who has been accused of having multiple inappropriate extramarital relationships with women (five of which are anonymously referenced in the indictment), drinking on the job, and other unprofessional conduct, all of which his office has denied.

When put in front of a judge, Hunter largely blamed his wife for the alleged illicit spending.

What does the race look like? In November, Hunter will face Democrat Ammar Campa-Najjar, who worked in Obama’s Department of Labor and who has consistently out-fundraised him, in the California 50th District.

Since the scandal broke, Cook changed the district’s rating from Solid Republican to a much more competitive Lean Republican. Most recently, an internal Democratic poll showed Hunter and Campa-Najjar tied at 46 percent. Covering most of San Diego County, this is a traditionally conservative suburban-rural district.

Hunter’s Republican colleagues were reportedly encouraging him to drop his reelection bid a long time ago. But even if he did at this point, his name will remain on the ballot in California unless a judge orders otherwise, and Republicans will be unable to nominate another candidate.

A former Obama aide and US Hispanic Chamber of Commerce and Department of Labor employee, Campa-Najjar — whose parents are Mexican and Middle Eastern — supports fixing Obamacare, working toward Medicare-for-all, and passing a clean DREAM Act. He’s also one of several candidates who are not taking any corporate or PAC donations in 2018. The corruption scandal has become the center of Campa-Najjar’s race.

The Rod Blum extremely online CEO scandal, briefly explained

What’s the scandal? Blum failed to disclose his role as the CEO of a company called Tin Moon Corp., which the Associated Press reported in February was a violation of House ethics rules.

Tin Moon Corp., according to the AP, promised that it could “help companies cited for federal food and drug safety violations bury their Food and Drug Administration warning letters below positive internet search results.” Blum’s chief of staff also appeared in what seemed to be a false testimonial, posing as one of the company’s satisfied customers, the AP investigation found.

Blum initially told the AP that his failure to disclose his role with Tin Moon was an oversight and said that it was “not a functioning company” in 2016 — though the AP also found that during that very same year, a YouTube account with Blum’s name had uploaded a testimonial for the company.

More recently, the House Ethics Committee announced it was expanding its investigation into Blum, as CNN reported. Blum’s case was referred to the committee by the nonpartisan Office of Congressional Ethics.

Blum reiterated in a statement that he had made a “clerical error” in his disclosure forms; he also accused the “radical left” of waging a “crusade of personal destruction” against him, according to Roll Call.

What does the race look like? The Iowa First, which Blum has represented since 2015, was always going to be competitive, but since the ethics scandal broke, Cook has slid it from Toss-Up to the Lean Democratic column. Blum is a member of the archconservative House Freedom Caucus, but his district is actually D+1. It voted for Trump by less than 4 points in 2016, and Blum won it by 7 points.

State Rep. Abby Finkenauer, who is 29, is Blum’s Democratic opponent. She received the support of the DCCC in her primary, as well as national groups like Emily’s List and NARAL Pro-Choice America. She has also raised slightly more money than Blum so far.

Some much-too-early polling found Finkenauer leading Blum by a point or two even before the scandal news took off. Blum is already facing attacks from Democratic groups over the ethics scandal as well as his vote for the House’s Obamacare repeal bill.

It takes a lot for Cook to give the non-incumbent the edge in any House race. So the forecaster’s decision to rate the Iowa First as Lean Democratic is a strong indicator of how tough the road is for Blum from here.

Democrats’ 2018 message is that Republicans are corrupt

Earlier this summer, congressional Democrats unveiled one of their major campaign messages for 2018: They’re telling voters they will actually “drain the swamp.”

The platform is reminiscent of a message Democrats campaigned on in 2006, a midterm election year that also came after historic Republican corruption scandals and resulted in Democratic control in the House and Senate and a majority of governorships.

The platform polls well with Democratic voters. A July poll from the progressive Center for American Progress found that 54 percent of voters across 48 Republican-held congressional districts said the GOP was “more corrupt” than Democrats; 46 percent said Democrats were more corrupt.

With a number of high-profile corruption scandals implicating House Republicans unfolding in the final months of the election year, Democrats are banking on this message to bring them sweeping electoral wins once again. So far, Republicans in Congress have been happy to oblige.