Bad guy (Raymond Sellars): Alex, honestly, I mean you no harm. If I wanted to, I could have killed you a long time ago. I just aim this right at your head and blow it off.
Alex's wife: Sellars, please! Don't!
Bad guy: I mean, if I wanted to, I could just aim this at your little family and I could just kill them too. And really, there's nothing you could do about it because, let's face it, you're a robot.
Bad guy (Raymond Sellars): What's clear is that with just one system in place, we've cut crime by 80%. Just imagine if we put, I dunno, let's say 100 systems in place. And then, I want you to ask yourself, why are you holding us back?
Senator: Is that your plan?
TV show host(Pat): Thank you, Senator. And thank you, Raymond.
Bad guy: Thank you, Pat.
TV show host: Well, there you have it. Who could argue with that? Which begs the question. Has the US Senate become pro-crime?
Mr. Modal comes back again.
I have figured out all of "could" in this movie except for these two. Why not use "can" or "would" instead?
For the first one, if that "could" followed the previous ones, the sentence would be "there would be nothing you can do about it", I suppose.
For the second, is the sentence the same as "Who would be able to argue with that?