EXCLUSIVE: Read the Secret Emails of the Men Who May Run Hillary Clinton's Campaign

— -- For the past five years, a prominent Democratic operative who is a leading contender to manage a Hillary Clinton presidential campaign has maintained a private email listserv for friends and associates that carries a provocative name: the “Mook Mafia.”

The listserv, which one member said reaches more than 150 fellow campaign veterans, has been a means for Robby Mook and a close friend Marlon Marshall to stay connected with many of the operatives who would likely populate a Democratic presidential campaign in 2016. Mook and Marshall have both been mentioned as possible Hillary Clinton campaign managers.

Copies of a cache of the emails obtained by ABC News, and revealed publicly for the first time, show Mook and Marshall demonstrating an aggressive tone in rallying their friends behind political causes, in exchanges that are often self-mocking and sometimes border on being profane.

They include rallying cries to, in Mook’s words, “smite Republicans mafia-style,” and, to quote Marshall, “punish those voters.” Mook sometimes calls himself “Deacon” in the emails, while Marshall, now a senior White House aide, refers to himself as “Reverend” in many of the exchanges.

Their inside jokes sometimes come at the expense of fellow Democrats, including former President Bill Clinton. A November 2009 mock news release announcing the listserv in addition to a new website and an upcoming reunion for the “Mook Mafia” included a fabricated quote from the former president.

“The Mafia has finally built a bridge to the 21st century,” Bill Clinton is jokingly quoted as having said in an email that appears to have been written by Marshall. “This is even more exciting than walking through the back of the Bellagio.”

The private emails were provided to ABC News by a Democrat on the listserv who has worked alongside Mook and Marshall on previous campaigns. The person who provided the emails is, like the vast majority of those on the listserv, supportive of Hillary Clinton, but does not support the idea of Mook or Marshall holding leadership roles in a second presidential bid. They were provided on the condition of anonymity.

That the emails are emerging publicly reflects the ferocious intra-battle to populate the top positions of an expected Clinton campaign.

Neither Mook nor Marshall responded to requests for comment. ABC News first reached out to both men Thursday morning, by email and phone.

On one level, the listserv is a testament to the loyalty Mook, 34, has inspired over a decade in national politics. His resume includes stints on Howard Dean’s 2004 campaign, running a series of state efforts for Hillary Clinton’s 2008 presidential bid and managing Terry McAuliffe’s successful run for governor of Virginia last year.

Marshall is also a veteran of Clinton’s 2008 campaign. He joined Obama’s field operation after the primaries, and he then served in top positions for the Democratic Congressional Campaign Committee, often working alongside Mook along the way. He is now a special assistant to the president and serves as principal deputy director of the White House Office of Public Engagement.

The exchanges provide a window into the clubby and pugnacious motivational styles of both Mook and Marshall, two stars of their party’s universe of field organizers and operatives.

The two most-recent messages to the group came just last week, on Election Day. They included a reference to a team reunion that would likely be held in New York early next year.

The existence of a “Mook Mafia” of friends and loyalists who extend through Mook’s previous campaign work has long been known. Scattered references to the informal group have appeared in favorable Mook profiles, and a Politico story last week referenced the possible New York reunion that was mentioned on the listserv.

The emails themselves, though, have not been seen publicly before. Much of the email traffic on the listserv appears to have been mundane: announcing job openings and new assignments, advertising or seeking rooms for rent in battleground states and organizing reunions in places including Las Vegas and Columbus, Ohio.

In the more substantive messages, though, Marshall emerges as the more aggressive of the duo. Writing in January 2010 to urge fellow “mafia” members to work hard on behalf of Massachusetts Senate candidate Martha Coakley, Marshall offered “an overall big thank you to everyone on this list who continues to fight the good fight.”

“F U Republicans. Mafia till I die,” he wrote. “If you have just a few minutes, hop on that activate and punish those voters!” (“Activate” is an apparent reference to a software program allowing volunteers to contact targeted voters by phone from anywhere in the country.)

The following year, in confirming news that he would be taking a new job that would include a move to Chicago, Marshall offered special thanks to Mook.

“First, the mafia never separates, it just continues to grow and expand and move into other states in order to destroy Republicans,” he wrote. “A special thanks to none other than the namesake himself, Deacon Robby Mook. Without him, there would be no mafia and I for sure know I would not have learned as much as I have in this business and have this opportunity.”

Mook responded by announcing “mandatory” attendance at a goodbye party for Marshall at a Capitol Hill bar.

“It's true: Marlon Marshall is leaving our fold. Today is the day the grownassman [sic] grows up and leaves for America's Second City. I know this prodical [sic] son will return to the mafia manger soon enough to smite Republicans mafia-style,” Mook wrote.

“If you can't be here in person, join me in spirit by sending your words of love and encouragement to the Most High Grown Ass Reverend Marlon D as he embarks on his pilgrimage. Please believe and obey the beard.”

Both Mook and Marshall have been discussed as potential Clinton campaign managers, should she run for president. Another top contender, Guy Cecil, may have seen his chances damaged by last week’s Republican rout because Cecil was running the Democratic Senatorial Campaign Committee for this election cycle.