ABCD here, family is deeply rooted in the idea that muslim/islam influence is trying to take over india, is this a common sentiment...?

So I have some side of my family (we are gujurati) that firmly believe that muslims are trying to "take over india" through forced conversions.

This came up because I was talking about elon is an insane psycho(this side of my family thinks he's a hero, lol) who believes in the great replacement theory, that democrats is letting in immigrants(illegal or otherwise) to replace white people.

My family's response to this was that this is what is happening in india....I honestly thought they were kidding at first. This side of my family is very well educated, so I thought I could bring up the decline in muslim immigration to India, I thought I could bring up the fact that india is still 80% Hindu (2011 census)

But as per usual they said I have no idea what I am talking about and that I should stick to american politics (ironic, because that's what I was initially talking about) while talking to me like a child (i'm in my early 30s, lol)

Is this line of thinking...is it a common idea in India, do people really believe in conspiracies like this? I am going through a lot of thoughts right now, as I got older, a lot of these radical ideas started to "seep out" from them. It gets to the point where I do not like talking about politics or anything around them. Politics is important to me and I take a lot of pride in being able to discuss things with people, ESPECIALLY when they disagree with me. I think it's important to listen to people even if they don't share your views, if anything it's more important to do so.

Dunno, maybe I am just disappointed. Not sure how to react to any of this. Some of the things I have heard from family, and even in-laws who moved from India to the US....just blows my mind really.