Froma Harrop is a syndicated columnist. Follow her on Twitter: @FromaHarrop . The opinions expressed in this commentary are hers; view more opinion articles at CNN.

(CNN) Alexandria Ocasio-Cortez was not entirely wrong when she said , "In any other country, Joe Biden and I would not be in the same party," in an interview with New York magazine.

In this country, however, the two-party system ensures a wide range of views within a political label, and particularly within the Democratic one -- exemplified by Biden and AOC's contrasting views.

In the interview, the congresswoman who represents parts of the Bronx and Queens complained, "We're not allowed to talk about anything wrong the Democratic Party does." Nonetheless, she went on to complain that "Democrats can be too big of a tent" and that "they let anybody who the cat dragged in call themselves a progressive. There's no standard."

Perhaps AOC would be happier leaving for another party that let her set the standards.

While under the Democratic umbrella, she seems to have made it her mission to fight the "Democratic establishment." In particular, she has worked with a group called Justice Democrats, a small, grassroots organization that supports progressive Democratic candidates as part of a larger effort to transform the party in the image of politicians like AOC.

It's no coincidence that the far-left Democrats -- including AOC's three colleagues in "The Squad" -- were elected in very safe liberal districts . But the Democrats now control the House not because of a handful of radicals, but because 40 mostly moderate Democrats took seats from Republicans in 2018. Without those decisive victories, far fewer Americans would care what AOC has to say.

It's normal for Democrats to disagree with other Democrats on certain issues. But the most-left members of the caucus often engage in the narcissism of small differences, building hostility toward Democrats holding views that diverge in minor ways.

AOC's animosity toward Biden may be linked to her support for his rival Bernie Sanders, or may reflect a poor understanding of how progressive Biden truly is on certain issues.

Notably, AOC has positioned herself as a staunch warrior in the fight against climate change with her Green New Deal. The Sunrise Movement, a group she's worked closely with , has been questioning Biden at campaign events , alleging he's done little about the warming crisis. But Biden was in front on this issue before AOC entered grade school.

In 1986, when Biden was a senator and almost no one was talking about the environmental crisis facing us today, he introduced the first climate change bill in Congress , directing the president to form a task force on climate change. The bill died in the Senate, but a year later a similar one was passed and funded.

As Barack Obama's vice president, Biden was point man on setting regulations limiting coal plant and tailpipe emissions. He was instrumental in getting the US to join the 2015 Paris agreement, the most comprehensive international climate action to date.

On AOC's second big policy priority, health care, Biden has also been quite progressive. He's been campaigning on a vision for improving health coverage by adding a public option to the federal exchanges established under the Affordable Care Act, which he helped usher in as VP.

A public option would be a government-run health plan competing with the private offerings. It was considered such a radical idea during the ACA debate, that Obama couldn't even round up enough Democrats to get it passed.

To be certain, AOC has proposed a more progressive approach to health care: a single-payer system with no room for private insurers. A single-payer system would simplify the delivery of health care and could more easily cut costs, but it also doesn't seem to be especially popular with Americans, who by and large want to retain the option to stay on their private plans. Adding a public option to Obamacare would allow Americans to do so while also forcing private insurers to compete with a government plan on price and benefits.

Nonetheless, when asked by New York magazine what her role in Congress might look like in a Biden administration, AOC groaned, followed by "Oh, God." That is not a response one would expect to the prospective election of a member of her own party. Without betraying her beliefs, AOC could have graciously said, "I look forward to working with a Democratic president."

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Ocasio-Cortez most likely doesn't have the guts to leave the Democratic Party probably for the same reason that Bernie Sanders ensures he has the "D" after his name whenever he runs for office. In the 2006 and 2012 Senate races, Sanders ran as a Democrat in the primary , then refused the nomination when he won so he could run as in Independent without facing a Democratic challenger.

AOC might also want to also have it both ways, using the Democratic designation to get elected in her liberal district while bashing the party that gave her power.

If AOC identified as a Democratic Socialist in 2020, she could conceivably win reelection to Congress, given her celebrity and her genius on social media. And she wouldn't have to be in the same party as Joe Biden. Why doesn't she try it?