That being said, one of ICE's favorite places to grab people, over the past year, is at immigration court, when people are complying with the law by showing up for their hearing on their asylum claim. I am not going to say that scenario is impossible, because we have seen so many things happen over the last several years, that would have been deemed impossible, in the late 70s.

They show up at immigration court because there's lots of undocumented folks there. Undocumented people have to go to immigration court. It's a target-rich environment, so they can make their quota of detaining as many folks as possible. I mean, sure - they're grabbing mostly rules-compliant and otherwise law-abiding folks (the ones who voluntarily show up for hearings). But that's so much easier than going after violent criminals! It's just efficient!

But that's not true at a polling place. There's little reason for people who are undocumented to go there. Even if you subscribe to conservative fever dreams about the undocumented voting in large numbers, they're pretty unlikely to do that via in-person election day voting, rather than other methods.

And I think you're wrong about the late 1970's. Those folks were in the immediate aftermath of Watergate and ABSCAM - I doubt there's much going on today they would have thought impossible. At best unlikely, but certainly within the realm of possibility. Other than the Russia stuff.