When the House Ethics Committee announced in July that it would formally investigate whether Nevada Senate candidate Rep. Shelley Berkley (D) broke any House rules or laws when she intervened to save a kidney transplant program, Democrats moved catlike to limit the potential damage.
Berkley hit the air immediately with advertising that tried to downplay the probe, and the party apparatus braced itself for a fall showdown, reserving $2.3 million in pre-election airtime.
It was a potent example of how alleged wrongdoing in Washington, D.C., can dominate the rhetoric of local races, even if the probes aren't likely to influence the outcome.
Congressional ethics investigations have factored into a handful of contests this fall, none more so than in Nevada, where Berkley, a seven-term Congresswoman, is locked in a high-stakes race to unseat Republican incumbent Sen. Dean Heller. Other lawmakers grappling with fallout from ethics inquiries include Reps. Michael Grimm (R-N.Y.) and Vern Buchanan (R-Fla.).
The House Ethics Committee decided unanimously that Berkley's role in trying to save a kidney transplant program merited a formal investigation because her husband's medical practice had a lucrative contract at the hospital and owned dialysis centers throughout the state.
Polls show the lawmakers neck-and- neck, and some observers say the Congressional ethics investigations will not be the deciding factor when voters cast ballots in November.
Republicans nonetheless promised to keep the ethics issues front and center.
"Since Berkley entered the political arena, we've seen a long pattern of ethical questions surrounding her career, and voters will soon decide if they want someone - like Ms. Berkley - who puts her own financial and political interests first," said Jahan Wilcox, a spokesman for the National Republican Senatorial Committee.
That news was quickly overtaken by the FBI arrest of Grimm's former top fundraiser on charges of lying on immigration documents and revelations that the freshman lawmaker failed to report a privately funded trip to Cyprus.
The OCE is limited to investigating the conduct of a sitting Member, and most allegations about Grimm have focused on fundraising activities before he was elected to Congress. House Ethics has in the past taken action on matters related to freshman lawmakers' campaigns.
A Democratic poll released in August showed Grimm tied with his opponent, Mark Murphy, a former Congressional aide and the son of former Rep. John Murphy (D-N.Y.). A memo released by the polling firm Global Strategy Group noted that "negative communication against Grimm is extremely effective," and Democrats have acted accordingly, focusing on Grimm's perceived ethical lapses in an advertising campaign on the Staten Island Ferry and a recent Web video. Grimm is running for a second term in a competitive district made up of Staten Island and parts of Brooklyn.
"Every day, voters raise Congressman Grimm's ethical issues to Mark and his volunteers," said Adam Haight, Murphy's campaign manager.
Grimm had raised five times as much campaign cash as Murphy, with nearly $1.3 million on hand as of early July. Carol Danko, a spokeswoman for the Grimm campaign, dismissed the accusations as politically motivated.
"Voters are united in their message: They want jobs and a stronger economy, which is why Congressman Grimm hasn't really been affected by the malicious smear campaign," she said.
The House Ethics panel announced in July that it had closed one of its matters related to the three-term lawmaker and would take no further action against him for omitting information on his annual financial disclosure forms. But the committee is also considering more serious allegations involving a $3 million settlement Buchanan made with a former business partner in exchange for him filing a false affidavit with the Federal Election Commission.
Elsewhere, a years-long investigation of Rep. Maxine Waters (D-Calif.) has not interfered with her re-election.
Also in California, Democratic Rep. Laura Richardson was already facing an uphill battle against fellow Democratic Rep. Janice Hahn before back-to-back ethics probes all but sunk what remained of her campaign.
Eric Herzik, professor of American politics at the University of Nevada at Reno, said the proliferation of ethics-related charges from government watchdog groups has made it difficult for the average voter to distinguish serious violations from more technical issues.
"You've had so much thrown out there that the public is now not as shocked," he said. A Congressional ethics investigation is "certainly not a good thing, but it's not that kind of flare in the night that it used to be."
Indeed, federal and state probes seem to be carrying more weight with voters this year.
The mood this summer at the campaign headquarters of his opponent, former Miami-Dade Democratic Party Chairman Joe Garcia, was almost jovial. "We just got through a primary and our opponent is under investigation," a Garcia spokesman said. "FBI and IRS are not usually acronyms associated with winning campaigns."
Rivera's campaign said in a statement that voters would reject any false allegations against the first-term lawmaker.
Senate Minority Leader Mitch McConnell, R-Ky., carries a musket on stage as he speaks during the American Conservative Union's Conservative Political Action Conference (CPAC) at National Harbor, Md., on Thursday March 6, 2014.