How would you defend what she has done from a charge of obstruction?
Intent, letter of the law criminal conduct.
So, let's make sure i know what you mean by "what she has done". Please clarify. Because what holman says is that she put out some sort of general materials about how to stay in the country. So, among other things...
1. To have obstruction, you have to have obstruct something specific -- an official proceeding, a specific investigation, etc. Here, I've seen or heard nothing , and Holman's comments don't suggest anything, along those lines. So first from a simple process perspective, issuing some general guide in the abstract simply ain't obstruction. For example, consider a hypothetical where ice is going after an illegal - let's call him Phenomenelio Frantastico - and Phenomenelio has never seen nor heard of AOC or her programs. Has AOC obstructed ICE's investigation or arrest of Phenomenelio? I don't think so.
2. Now of course I have no idea what whatever she put out actually says. But, let's just say I have my doubts - notwithstanding AOC's stupidity and ego - that it suggests some vigorous network of safe houses, sources to access to fake documents, or the like. Rather, I'd bet that it includes things like advocacy hotlines and the like.
3. I also don't know much about the context of her publication. Depending on what those are, she may be simply immune under the speech and debate clause.