The hacker known as Guccifer 2.0 has posted several emails from Republican Party officials and staffers on a site associated with Russian cyber-warfare.

The Hill:

Most of the messages coordinate campaign activities, solicit funds, or invite or RSVP to events. The archive is largely the procedural minutia of running campaigns or state parties. 

The emails include a wide array of constituent email addresses. Many appear to be responses to mass-emails from concerned party supporters writing in to their delegates. One reply to a Stop Hillary PAC fundraising email targeting Democrats lack of support for the Benghazi commission reads, "Don’t the Republicans have a majority in Congress? Isn’t John Boehner a Republican? What is the problem that you need my $36 to help you fight back."

The archive appears to be incomplete, with replies to emails that don't appear to be included on their own. That could mean the emails were deleted before being retrieved, or that the leaker or site decided to scrub certain items from the record. 

But that there was a leak at all runs counter to a Republican narrative that the DNC is particularly susceptible to data breaches (“What is it with Democrats that they can't maintain basic email security?” Mike Huckabee asked on Facebook).  

Guccifer 2.0 is thought to be a front name for Russian intelligence, and the site has strong circumstantial ties to the Russian group believed to be behind the hack of the Democratic National Committee (DNC).

DCLeaks claims to be the work of patriotic American activists but is written in a way that suggests non-native English speakers. Much of the leaks are email archives from critics of Russia.

The site hosts a trove of leaked emails from Gen. Philip Breedlove, who was heavily in favor of fending off Russia during its Ukraine incursion, and George Soros, whose DC Leaks emails were promoted by the site on twitter as “Check George Soros's [Open Society Foundation] plans to counter Russian policy and traditional values.” 

DC Leaks site was initially registered by THCServers, a company that has only been the initial registrar for 14 sites since 2013. Including DC Leaks, three of those sites have been connected to the Russian hackers believed to be behind the DNC hack, including a site identified by the German government.

The emails were released on the same day that a treasure trove of personal information on Democratic lawmakers was also posted.  Cell phone numbers, personal email addresses, and other private information were exposed in the hack.

The release of GOP emails isn't damaging, but that's not the point.  The hackers are demonstrating a capability that, if they haven't already, could lead to a much more serious exposure of GOP secret communications. 

The FBI has known about the DNC hack for a year but didn't publicize it because the national technical means used to discover the breach is top secret.  So in the end, neither party was given a chance to tighten cyber-security of their tech operations, the lack of which led to embarrassing disclosures.