No, it is a request for someone to define what they understand as a “liberal”, as that term gets bandied about in many different contexts as some sort of boogieman. To have any sort of sensible discussion there needs to be a common understanding.

Sealioning is a type of trolling or harassment that consists of pursuing people with relentless requests for evidence, often tangential or previously addressed,

A single questions is “relentless”?

And, what you have demonstrated instead, is an example of an ad hominem attack. Here, ill even provide you the definition from the dictionary.

Attacking a person’s character or motivations rather than a position or argument. “Debaters should avoid ad hominem arguments that question their opponents’ motives.”

OP has used the term “capitalist liberalism”. The right continuously attacks “libs” as being “socialist”. Hence my question as to what OP even means