Ocasio-Cortez’s victory “seems likely to hurt Congress, America and the Democratic Party,” Lieberman, a Connecticut Independent, wrote in a Wall Street Journal op-ed. He encouraged voters to support Crowley, whose name, as of now -- through a quirk of New York election law -- will appear on the ballot as the nominee of the Working Families Party.
Crowley has insisted he’s not running and has stated his support for Ocasio-Cortez. However, in a Twitter feud last week, Ocasio-Cortez said Crowley intends to mount a third-party challenge to her general election campaign in November.
Lieberman is currently senior counsel at Kasowitz Benson Torres LLP, the law firm of President Trump’s longtime lawyer Marc Kasowitz. In 2006, he lost the Democratic primary for Connecticut senator to Ned Lamont, who ran against hawkish Lieberman on an anti-war platform.
Unlike Crowley, Lieberman had discussed a backup option before his primary defeat, resolving to campaign as an independent if he lost. Immediately following Lamont’s victory, Lieberman vowed to campaign through November, and he went on to defeat Lamont in the general election, running as an independent on the “Connecticut for Lieberman” ticket.
Wednesday morning, Crowley tweeted: “Still not running.”
Crowley has said he will support Ocasio-Cortez and even sang “Born to Run” in her honor after her victory.
“So much for “Born to Run,” Ocasio-Cortez tweeted last Thursday in reference to Crowley’s refusal to take his name off the ballot.
The Working Families Party, caught in the crossfire, had originally endorsed Crowley in the primary but has since enthusiastically backed Ocasio-Cortez.
On Wednesday, the party strongly disavowed Lieberman’s opinion piece on Twitter, writing that New York voters shouldn’t take their cues from the ex-Senator.
In the same thread, the party wrote: “We asked [Crowley] to remove himself from the November ballot, but he refused.”
If Crowley decides to be removed from the ballot, his clearest option is to be nominated by the Working Families Party to a different race.
Bill Lipton, the Working Families Party’s New York director, told ABC News that the party offered Crowley an alternate endorsement in order to vacate the ballot line, but Crowley declined.
“There are routine procedures to remove candidates from the ballot in New York, and we were disappointed that Crowley refused to work with us to get off of the ballot line,” Lipton told ABC News.
Crowley's presence on the ballot is unlikely to affect the outcome of the race.
“It’s a ballot switcharoo charade [Crowley] doesn’t want to participate in, and he’s endorsed her, and there’s no doubt that she will win," veteran election lawyer Jerry H. Goldfeder told ABC News.
As of now, however, Crowley will remain an option for voters. A campaign spokesperson for Crowley declined to say whether he intends to remove his name from the ballot.
"Joe Lieberman has every right to his opinion. Joe still isn't running," the spokesperson said in a statement to ABC News.
Ocasio-Cortez, who is a card-carrying member of the Democratic Socialists of America, defeated Crowley by a 15-point margin after campaigning on a left-wing platform of social and economic justice.
In his article, Lieberman argued that Ocasio-Cortez will shift the Democratic party too far left, imperiling Democrats’ chances to take back the House and Senate in upcoming midterm elections.
“If Democrats are to regain a majority, it will be by winning swing districts with sensible, mainstream candidates,” Lieberman wrote, pointing out that Nancy Pelosi has distanced herself from the left-wing insurgent.
In a further twist, Lamont, the candidate who defeated Lieberman in the 2006 primary, is currently running for Connecticut governor against Bridgeport Mayor Joe Ganim. Lamont is heavily favored to win.
The Ocasio-Cortez campaign declined to comment, and Lieberman did not respond to a request for comment.