Then his boss, Hillary Clinton, lost.
Within 48 hours -- infuriated by the Cabinet prospects being floated by Donald Trump's transition team, like Wisconsin sheriff David Clarke for homeland security secretary -- Petkanas had decided he couldn't change careers yet.
"Tuesday was the election. Wednesday I was sleepless and tired and very sad," he said. "And Thursday I got extremely angry."
Petkanas quickly transitioned from Clinton's director of rapid response -- a role that made him the campaign's chief Trump hit man -- to director of the Democratic National Committee's war room, where he'd lead the party's resistance to Trump's actions.
"The signals that were coming out of the White House lit a fire under a lot of people," Petkanas said. "He re-engaged a whole slew of people, talented people, driven people, to stay in the fight."
In the three months since her defeat, Clinton has mostly faded from the political stage. She has tweeted support for the Women's March
last month and criticized Trump's moves
to limit immigration.
But many of her former staffers -- especially mid-level Brooklyn veterans -- are now on the front lines of the left's anti-Trump resistance.
Many say they're apoplectic over revelations
that top Trump advisers were in constant contact with Russians known to US intelligence during the campaign.
Some ex-Clinton staffers have moved into Democratic organizations that are shifting their focus to opposing Trump -- such as Clinton press secretary Brian Fallon, now a senior adviser to Priorities USA; policy adviser Corey Ciorciari, now helming the Center for American Progress war room's policy and research efforts; and Cristobal Alex, Clinton's national deputy director of voter outreach and mobilization, who is now the president of the Latino Victory Fund.
Others are racing to fill the holes in the Democratic Party exposed by November's results, in an effort to help activists newly energized by Trump's victory strike back in upcoming elections, at congressional town halls and more.
Clinton veterans' new projects
One example many Clinton veterans point to: Run for Something, which launched on Trump's Inauguration Day with the goal of recruiting, training and funding first-time candidates for office.
It was co-founded by Amanda Litman, the Clinton campaign's email director, who said in the immediate aftermath of the election, she was looking for a new challenge after several years in online fundraising.
After the election, though, she said she and other Clinton staffers felt like they had failed.
"Once we got over the shock and the sadness and the heavy drinking -- catching up on sleep, cleaning my apartment for the first time in six months -- a bunch of us were talking about different things," she said. "Do you stay in politics because it's incredibly important? Do you leave because you're so cynical and jaded and feel like the work we've been doing doesn't matter?"
Once Litman chose the first option, she leaned heavily on Clinton campaign staffers.
She said Run for Something was built through volunteer efforts of Clinton veterans: The campaign's website director built Run for Something's website for free; Clinton's finance team helped Litman figure out how to raise money. Many of its 1,000 operatives who have volunteered to help future candidates are Clinton alumni.
Litman said friends asked her why she wasn't spending more time going out and relaxing after the election. But she came to feel like she had two options: working, or yelling at the television as news of Trump's transition moves came in.
"One is productive and one scares my dog," she said.
Fueling the Trump resistance
Litman met her co-founder, Ross Morales Rocketto, through his wife, former Clinton digital staffer Jess Morales Rocketto -- who is now organizing airport protests and consulting for United We Dream and the National Domestic Workers Alliance in fighting Trump's executive order banning immigration from seven majority Muslim countries.
Other Clinton staffers are filling out the offices of rising Democratic stars like California Sen. Kamala Harris -- who hired ex-Clinton aides Lily Adams and Tyrone Gayle to lead her communications shop. Washington Rep. Pramila Jayapal hired Clinton veteran Omer Farooque as communications director.
Clinton campaign rapid response team veteran Jesse Lehrich is leading communications for Organizing for Action, while Clinton rapid response spokeswoman Adrienne Watson is the Democratic National Committee's national press secretary.
Another former Clinton communications staffer, Xochitl Hinojosa, is advising former Labor Secretary Tom Perez -- who has called on party members to treat Trump as Senate Majority Leader Mitch McConnell treated Obama, opposing him at every turn -- in his bid for Democratic National Committee chairman.
Jimmy Dahman, a Clinton field organizer in Iowa and then Ohio, has launched TownHallProject.com -- where he and a team of volunteers have made a point of tracking every town hall, coffee meeting or other opportunity for constituents to reach their congressional delegation.
His site's database of upcoming meetings has served as a crucial tool for progressives to identify upcoming events to attend and protest.
Dahman decided to launch the volunteer-driven project after watching a crowd of 100 spontaneously show up at a town hall held by Rep. Mike Coffman, R-Colorado, to protest his support for repealing Obamacare.
"I thought, I wonder how many people feel the same way but didn't know the event exists," he said.
Former Clinton deputy national press secretary Jesse Ferguson, senior adviser Leslie Dach and communications department chief of staff Lori Lodes are all consulting for Protect Our Care, the coalition fighting Trump and congressional Republicans over the future of the Affordable Care Act.
Ferguson cited Clinton's oft-repeated Methodist creed -- "do all the good you can, for all the people you can, in all the ways you can, as long as ever you can."
"It's one that many of us took to heart," he said. "There's no better example for the idea that you get knocked down, you have to pick yourself back up. She taught us that and, for a lot of the staff, they're going to go and live that idea."