Republican presidential candidate Mitt Romney smiles as he is booed after saying he will repeal "Obamacare" at the NAACP convention in Houston July 11, 2012. (REUTERS/Richard Carson)

This item was originally posted on Sept. 3 and has been updated with the latest politician to fall victim to the trend: the Republican Senate nominee in Georgia, David Perdue, who once said he "spent most" of his career on outsourcing. 

There are plenty of reasons Mitt Romney lost to President Obama in 2012, but here's a big one: the brutally effective campaign to paint him as a stiff, out of touch millionaire that he painfully reinforced in his infamous "47 percent" video.

The same formula that felled Romney threatens to derail some of the most promising candidates of the midterm campaign.

The latest to open himself up to Romney vintage attacks is David Perdue. Politico reported Friday that during a 2005 deposition, the GOP Senate nominee in Georgia was asked to describe his experience with outsourcing and responded, "Yeah, I spent most of my career doing that."

Perdue's campaign manager told Politico that by "outsourcing," Perdue was referring to a “company contracting with an outside source, not the direct shift of jobs overseas.” But that explanation may leave many unsatisfied. And it's not likely to stop Democrats from seizing on the comment to add to a narrative they've already started building.

Michelle Nunn, Perdue's Democratic opponent, has run an ad accusing Perdue, the former chief executive of Dollar General, of profiting off others' misfortunes. The firm that produced the ads crafted strikingly similar anti-Romney commercials for the Democratic super PAC Priorities USA.

Perdue is one of a handful of candidates running in key battleground races who are vulnerable to the same kinds of attacks Democrats lobbed at Romney in 2012. From Democrats Bruce Braley in Iowa and Sean Eldridge in New York to Illinois Republican Bruce Rauner, history could repeat itself in some of the most pivotal midterm contests.

Rauner, the Republican nominee for governor of Illinois, acknowledged to reporters  last month that he belongs to an exclusive wine club that costs more than $100,000 to join.

Rauner is viewed widely as the Republican with the best chance of unseating a Democratic governor. Democrats have been trying to build a he's-just-like-Mitt narrative around him to save Gov. Pat Quinn (D). Rauner, who made more than $50 million in 2013, has unintentionally fueled their attacks with head-scratching comments like the one he offered to the Chicago Sun-Times in March to describe his wealth: "Oh, I’m probably .01 percent."

Democrats have long been eager for any chance they get to cast Rauner as the Romney of 2014. The Democratic Governors Association released a video in August tying the two together and accusing Rauner, a former private equity executive, of outsourcing jobs.

It's not just Republicans getting stung by Romney-style broadsides. To wit: Braley. He's not a mega-rich businessman like Perdue or Rauner. But like Romney, he was caught on camera making comments that instantly raised questions about how tone deaf he was to the lives of everyday Iowans.

In March, footage of Braley, a lawyer and congressman, disparaging Sen. Charles E. Grassley (R) as a "farmer from Iowa" at a private fundraiser became his own version of Romney's infamous "47 percent" video. It laid the foundation for a series of GOP attacks on Braley's appeal to working class Iowa voters that have transformed what once looked like a contest that tilted Democratic into a real GOP pickup opportunity.

Eldridge, the husband of Facebook co-founder Chris Hughes and Democrat challenging Rep. Chris Gibson (R-N.Y.), made headlines for all the wrong reasons this spring when he and his campaign dodged a Politico reporter eager to ask him questions about his investment firm.

All these examples reveal something important about 2014: Despite the all the discussion about President Obama weighing down Democrats and far-right Republicans foiling GOP candidates, personal attacks and missteps could be just as toxic on Nov. 4 -- if not more so.

If the personal complications become lethal in November, they could have far-reaching consequences. There are few races as pivotal in the battle for the Senate as Iowa and Georgia. There are no Democratic governors as vulnerable as Quinn. And Gibson's race won't tilt the majority, but it's one national strategists in both parties have been eyeing for months.

No matter the larger political climate, it never bodes well for a candidate when the public views them as out of touch. And sometimes, as Romney learned the hard way, it's enough to sink them.