Former Democratic Sen. Joe Lieberman (Conn.) penned a stinging rebuke of New York Democrat and congressional candidate Alexandria Ocasio-Cortez this week.

Her "surprise primary victory over Rep. Joe Crowley seems likely to hurt Congress, America and the Democratic Party," Lieberman wrote in an op-ed published in the Wall Street Journal Tuesday."

A member of Democratic Socialists of America (DSA), Ocasio-Cortez defeated Crowley, the House Democratic Caucus chair, in a primary for New York’s 14th Congressional District last month. She advocated a federal jobs guarantee, single-payer Medicare-for-all, and the abolishment of Immigration and Customs Enforcement (ICE).

"Because the policies Ms. Ocasio-Cortez advocates are so far from the mainstream," Lieberman argued, "her election in November would make it harder for Congress to stop fighting and start fixing problems."

"Her dreams of new federal spending would bankrupt the country or require very large tax increases, including on the working class," he added.

Lieberman, who now considers himself an independent, also attacked Ocasio-Cortez’s views on foreign policy:

Ms. Ocasio-Cortez didn’t speak much about foreign policy during the primary, but when she did, it was from the DSA policy book—meaning support for socialist governments, even if they are dictatorial and corrupt (Venezuela), opposition to American leadership in the world, even to alleviate humanitarian disasters (Syria), and reflexive criticism of one of America’s great democratic allies (Israel).

Ocasio-Cortez stumbled over a response to a question about the Israeli-Palestinian conflict last week, admitting "I am not the expert on geopolitics on this issue."

The democratic socialist has accused Crowley of mounting a third-party challenge since he has not removed his name from the ballot. Crowley’s name will appear in November as the candidate of the Working Families Party (WFP). The congressman responded by pointing out that complicated New York election laws make it difficult to remove one’s name, and he reiterated his support for her. Lieberman, however, hopes Crowley will consider actively campaigning as the WFP candidate.

"Joe Crowley’s re-election would be evidence that Democrats are capable of governing again," Lieberman wrote. "I know him as a bridge builder and problem solver, which is exactly what Congress needs more of in both parties."

"For the sake of Congress and our country," he concluded, "I hope Joe Crowley will give all the voters of his district the opportunity to re-elect him in November—and I hope they find his name on their ballots."