Possible, but even as a joke, this is a bit of a wrong sign, and note that cops must be seen as an example. How can cops be credible when they threaten over social media or like threatening posts?
When the police loses credibility it will be harder to tell the civilians they should not violate the law? A cop has to give the right example. The impact it can have on society when cops do not behave is rather great. I can understand he's angry with Ocasio-Cortez, and he may express that anger also, but there is a limit, and when it comes to liking posts. I've met people who have a record and mostly they know all the cops better than the one in charge of the police, so I know by this experience. And since likes are public on most social media... well... That does bring the police in discredit.
When you are in a public function like that, your actions do have impact. Being a former moderator of several big communities, I could already see how people (particularly the ones who were close to getting banned) kept their eye on me. When you are a cop, where the violations you deal with are normally greater than when you are a site/chat/forum moderator, this counts even more....