I am of the opinion that not discussing these things is an analog to the Paradox of Tolerance, if not being exactly what the Paradox is about. If we don't discuss the hatefulness, then the hateful think they are doing fine.

Attacking only causes people to "dig in". Passive aggressive actions will make you look weak.

Being cordial while also calling out instances of hate as they occur would likely be fine. Be strong and confident, but keep corrections short and to the point (Imagine correctly a 5 year old. Understanding and care, not anger, and keep things in reality.) "That didn't happen.", "Why would a criminal say that?", "Toddlers visiting basketball plays, will reduce the average height, but no one gets shorter or taller."

However she has become more racist and judgemental (anti-trans etc) in recent years. Hates Joe Biden and Kamal Harris but can't or won't say why.

I’m gonna guess that it’s because she watches Fox “News”, and that she can’t say why she hates Biden and Harris. She’s simply heard so much anti-Democrat rhetoric that she’s parroting it.

Ethically, the choice seems easy. While specific events may be unpredictable, the themes of hatred and authoritarianism were obvious to anyone who was genuinely paying attention during the campaign. They knowingly voted for a complete piece of shit. They voted for someone who had tried to overthrow the government when things didn’t go his way. He had already been convicted of bribery and sexual assault before the election even took place. The man is simply unfit for office.

Your level of resentment is by no means “locked in”. You have every right to be angry.

The best thing you can do is communicate. Talk with your wife. Show her your post. Don’t keep your resentment bottled up - that’s not healthy. Hopefully, the two of you can come to a solution that doesn’t harm your marriage. If her family doesn’t like it, too bad. Through their (deliberate?) ignorance, they helped create this problem in the first place.

For your spouses sake, just stfu and dont engage with her regarding politics. Ask your spouse how she wants you to be, since the mother-in-law visiting is performative for you anyways, and you love your spouse more than you are obligated to tolerate your MIL.

Resentfulness is a reaction, not a position to take.

You can either say "she's not welcome" or "we agree to disagree and will not discuss it" and then stick to it. Your choice. But letting (welcoming?) her into your home and then resenting her presence is childish.

Take a stand, one way or another. If you let her come, then deal with it like an adult.

With my ex MIL I stay friendly because she's great in so many ways, and just act completely ignorant when she says something awful, for example:

ExMIL: I'm looking for a church but can't find one that is Christian enough.

Me: Oh, I understand. So many are just so worldly now and not at all Christ like, they don't welcome the stranger, they do that prosperity gospel nonsense, culture war bullshit instead of good works. That makes sense.

ExMIL: oh I meant they are too progressive, too loosey goosey (Paraphrasing)

Me: Huh?

Or

ExMIL: I don't understand this trans nonsense.

Me: I know, right? Who gives a fuck what someone else says they are! You say you are a boy, you are a boy, it doesn't have any effect on anyone else, I don't understand the drama around it, at all.

Basically whenever I get a chance I just intentionally misinterpret it like there is no possibility that she meant that, because nobody could possibly mean that.

I have a similar situation and I've landed on "my first duty is to my wife." What that means to you may be different than what it means to me, but that's where you should start IMO.

To the TL;DR question, absolutely it's ethical to be more upset as more bad things happen.

If your MiL voted for Trump, then she's a filthy MAGA, stop making excuses for her. Live your normal life, yell at the news, complain loudly every time you hear another one of his inane statements, criticize loudly and often.

That's what it's like in a normal, patriotic American household. Make her live like a real American, and not in her imaginary alternative MAGA reality, and stop coddling her treason. Tell her you won't tolerate talk of treason, racism, etc. Call her out EVERY time, and tell her it's unacceptable in your house, and in YOUR America. You can say ANTHING YOU WANT, but she has to keep her treason to herself. Period, no negotiation. Freedom of Treasonous Speech does not have to exist in your house.

If she doesn't like it, she can GTFO. We should no longer tolerate any MAGA bullshitp. It's time to push back HARD, and don't stop.

fill your house with tons of progressive decorations. Lots of lgbt+ and such and a painting of biden above the mantel. really do it up. then have her visit as much as she likes.

Put a rainbow flag in the room where she sleeps. 😋
Maybe a picture of Reagan with quotes of how Russia is the enemy, and tariffs are bad for everybody.

Depends on how much you value your wife.

You don't have to agree with your family's politics. It's basically guaranteed a huge chunk will disagree with you on something. Just don't talk about politics with them since it upsets you so much.

It's perfectly reasonable to steer the conversation away from politics if it comes up, and if they insist, particularly at your house, be a bit more direct about not having political discussions over the dinner table.

Just make sure she’s aware of the consequences of her actions. The amount of detail or tangentiality is up to you. If she’s smart she’ll STFU about it and it can be civil, if not cordial. But feel free to pull out the “I’m glad you like it when they zip tie kids” as needed.

These people are guilty of crimes against humanity many times over. Crimes against the American people, war crimes, treasonous acts against the constitution...you name it.

You shouldn't feel obliged to entertain people who support that. Zero consequences for these people means zero reconciliation for their atrocious behavior.

In the wise words of Christopher Walken:

I don’t think it’s unreasonable to want to avoid your MIL. I also think it’s reasonable for your wife to maintain the relationship.

Can you use her visit as excuse to take a vacation—alone or with friends—or visit your family? Given the circumstances, I think avoidance is a perfectly valid option. Get some you time if your wife is cool with it.

I think any response (short of something like physical assault) is probably ethical. Think about your mental health and your wife's opinion on it too.

I hate my in-laws for similar reasons. (My wife dislikes them too.) We all have a very spoken no politics rule when we visit. This makes family gatherings more tolerable. We only see them maybe 4 or 5 times a year. We've definitely seen them less as things got worse politically. Last year we even skipped Thanksgiving with them.

Nazism isn't really an ideology I can tolerate

I don't think this is an ethics question, you're asking whether resentment builds or fades over time and the answer will be very specific to each person and case. That being said there's one thing I would like to point out:

a person does X, I express disapproval. Is it ethical to express MORE disapproval as additional unforeseen consequences of X become apparent?

Those weren't unforseen, that's the worst part for me, they were clearly foreseen, foretold and warned about, and I could potentially be persuaded to believe people were unaware of that the first time around, but by the second time you are obviously okay with all of it.

To your edit... it rather sounds like she is in fact MAGA and doesn't want to admit to the "why". there's really not very many people who were both willing to vote for trump a second time and aren't MAGA, even if they don't want to admit it.

from an ethics stand point, I'll remind you of an old german saying. "If 10 men are sitting at a table with a nazi, you have 11 nazis." You cannot look at trump and honestly conclude he's an acceptable (never mind good,) president without also agreeing with his fascist and tyrannical bullshit. if she's genuinely unhappy with the status quo, she can show it by protesting or something. Until then, she's still a trump supporter and still part of the problem, and there is zero excuse for not knowing what he was about. he said he was going to do everything that he's doing. (well. maybe not the ballroom or shitting himself, but details.)

but none of us are the ones you need to be having this conversation with. we can't decide what's right here... that's a personal decision you need to make with your wife.

It's your and your wife's home. So your rules apply. Make that agreement with your wife beforehand. So there are no fights afterwards.

Things like;

1. She must not address you. Basically act as if the other person does not exist.
2. The visit will be as short as reasonably possible. For longer bouts with her daughter, your wife can visit her mother.
3. She must be humble and accept the extreme difference in views.

Sooooo, you're letting a nazi stay in your home. Your wife is the daughter of a person who chooses to still be a nazi. If you put it in that context, does it make it clearer?

Dude please please please don't let Trump ruin your marriage. Not allowing your MIL to stay for her annual visit when your wife wants her to is gonna be a big big problem

I think you married into a Catholic or Christofascist family. They clearly take the Mark of the Beast by obeying the Pope at least (in historicism, we believe and show that the Pope is the Antichrist). Your wife's family clearly participated in their own demise, which is why I didn't vote nationally, and instead, voted down ballot on the state level (again, to clarify, for my state, and not nationally, as national elections are selections).

Disclaimer: I'm not American so will never understand your culture towards politics as well.

I don't think it's fair to point at every bad thing Trump has done so far and say that's the fault of your MIL for voting for Trump. The way I see it as a non-American, Trump did say he was going to be a racist xenophobic piece of shit on his election campaign, but the media heavily downplayed this, and Trump still tricked and lied to everyone. Politics is weird like that: you can theoretically campaign on one thing but then throw everything out and do the opposite once you get elected.

Hating Kamala and Biden is a fair opinion to hold as well. I consider a vote for them as picking the lesser of the 2 evils, rather than voting on what's best for America, because both parties seemed awful to me (a non-American).

I think it's important that you try to at least understand and empathise with why your MIL voted Trump in the first place. You were very light on those details in your post, which I suspect is because you're very quick to judge someone based on who they vote for.

Maybe she really hated one policy from the democrats so voted for Trump? Maybe she bought all the lies Trump told during his campaign and regrets her vote strongly? Maybe she's a single-issue person who voted for Trump because of one policy and ignored everything else?