Besides your comment being some broad generalization, it fails to assert the reality of the 'world' and in its place takes a group of progressive first world countries which align with liberal politics.
The world includes such places as India, Pakistan, Africa and China, oh my, where liberal ideology is a far cry from what you are describing
It's rather strange to me that it is so hard for the term "radical left" to be defined in any sort of objective way, often it seems no definition is available at all which makes discussions about the topics hard to have.
What rights do Christians have over others?
Globally, supporting marriage equality puts you in the minority, both in terms of # of countries as well as per capita. [0] Personally I think it's an obvious right, but that doesn't make it popular.
[0] https://www.hrc.org/resources/marriage-equality-around-the-w...
No, that is not “radically far left.”
In 2019, according to Pew Research, 44% of “Republicans and Republican leaners” supported same-sex marriage.
As for your question about equal rights for “non-religious / non-Christians”, I’m not sure what you’re referring to. Can you elaborate?
> I ask it because the "conservative" party in the US explicitly is against such things in their platform documents.
I assume you’re referring to the Republican Party platform document? It’s quite large; can you identify the portions you’re specifically referring to?
P18 in the PDF (p11 as per the included numbering) condemns and calls for the reversal of both US vs Windsor & Obergefell v Hodges as well as calls for marriage to be between one man and one women only.
P 19/12 calls for special rights to worship "God" which is the Christian god in this context, it doesn't call for the same rights for other religious beliefs. It all calls out for special rights to display the Ten Commandments but not other religious artifacts / documents.
I’d suggest this recent piece as a very cogent breakdown of the lost ascendancy of the religious right in conservative politics:
https://www.nytimes.com/2022/06/01/opinion/republicans-relig...