I'm not so sure. The fella she beat in the Dem primary -- Joe Crowley -- is running as an Independent. He's held that seat a long time and I think his supporters will show up for the General Election (unlike the Primary, which had a very meager turnout).
It's happened before. Remember the Alaska Senate race several years ago. I can't recall the Republican's name at the moment, but he beat Lisa Murkowski in the Republican Primary. Unfortunately, Murkowski went Independent for the General, and edged out the Republican nominee. Yes, it was infuriating, but it goes to show there is a precedent for just such an occurrence.
She’s getting so much undeserved support just because she is female, young and socialist.
Obama redux.
Joe Miller
Not really. His name was placed on the ballot representing the Working Families Party and Crowley isn't going to comply with the arcane and complicated procedures to remove his name from the ticket. However, he has effectively ended his campaign, insists he is not running, and (sorta) endorsed Ocasio-Cortez saying "The Democratic Party needs to come together."