I have a pretty strict "No real world politics" rule. I am slightly more lax about it while everyone's setting up, but during game you shouldn't be looking up news or have time to talk about who's fucking up how in washington, you should be playing the game you're there to play. And because its an idealistic fantasy world, Jews don't exist there.
But I'll usually let them say their bit and then clearly shut down that line of discussion and redirect with some kind of "Ok, how's that related to what's happening in game?"/"Ok, cool. What are you doing in combat?"/"That sounds like something you can talk about after session, what are you doing in game?"
I've actually never had to warn anyone twice, so I'm not 100% sure to I'd do for 'strike 2'.
The closest I've come is (lefties) unable to shut up about the retards disrupting the US Senate vote confirming Biden's election. It was before session while I was waiting for some people to sit down at the table. To be clear, I thought the people who had 'occupied' the capitol were retards, but I was trying to untwist panties by pointing out to the melting down lefties that no one thinks democracy is under threat when state capitols get taken over by retards, or when there's a bunch of violent people on the mall outside the capitol. When it became clear I was not going to be able to logic people out of positions they didn't logic their way into, I just said "I guess you're free to feel that way. I don't think we're going to have a productive discussion on this and I really don't care to talk about it. Let me go see what's keeping the others so we can start." and left the table, which seemed to send the right message. When I got back, the munchkin player read off some purple prose from Reddit, while I listened to with no reaction and then said "Ok, cool. Anyway, so the party is..."
Re: Familiars, I usually stick to RAW stuff so tiny spiders etc usually are not on the list of valid familiars.
If I really felt like fucking with someone who did a spider familiar, I'd say "ok you see through your spider's eyes. You see a lot of blurs and colors." and if they were a clever asshole who made a jumping spider "anything beyond about 6 inches away is completely indistinct". This would still let them do the (in my mind) completely valid send it under the door to scout and see there's something waiting for them - just not exactly what.
IF they try to 'listen' "You are aware there are voices, but since spiders don't have ears, you can only sense vibrations - you can't actually make out any words"
And as
@Capsaicin Addict points out for one of many reasons I don't run 5e, most other games incur a cost for losing a familiar.