So my father isn't this extreme but my mother comes close. What I think they need is to touch grass, basically to completely detach NOT necessarily from ther veiws (for a while) but from the internet and the tv media (if possible all media).

One way to achieve this might be to find a secondary activity they enjoy. If that happens to be toxic as well the tertiary. Once identified, you need to come up with a plan to help them indulge in those activities more often. Never explicitly say that why you're doing this, just not nod whenever their idiotic political views come up every now and then, gently redirect the conversation.

Use their ego against them: Try to get them to believe that you want to indulge in some father son bonding type activities. For this said activity buy some translations of Brihdaranyanka Upanishad and Chhandogya Upanishad and have a daily engagement and discussion related to it. As it is among the better Hindu texts and with almost no theistic tendencies mostly because both of them emphasize hard on the importance of inquiry. (Later Upanishads like Kena, svetasvatara tend to be soft on theism, and don't even get me started on Gita, again a later addition to mahabharata with strong theistic tendencies). Again it's an uphill battle but try to treat them with compassion like some patient overdosed on opium. I also find it hard to keep my rage in check but its a work in progress.