There are loyal followers on both sides that would not waver for ANY reason. Period.
All you keep eluding to is people who are stuck on what they believe. That is not a cult. Joy Reid once recounted a conversation with a cult expert who put it best - when asked what's the difference between a religion and a cult he explained; 'in a religion, your savior sacrifices themself for you. In a cult, you sacrifice yourself for your savior'.
This explains MAGA perfectly. Just start by looking around at his inner circle; Michael Cohen, Steve Bannon, Rick Gates, and plenty others all convicted for crimes they committed for Trump (and many more to come). Giuliani, financially ruined. Lindsay Grahm, Elise Stefanic, and others sold their soul and now daily peddle nonsense they clearly do not believe. The entire republican party surrendering every principal it used to pretend to value, plus losing election after election and ready to do it again this year. Evangelicals completely abandoning the teachings of Christ to support Trump. Right wingers getting COVID and dying because they bought Trump's BS that COVID was a hoax. J6 rioters in prison because Trump told them to fight like hell. Trump's supporters donating their hard earned money to Trump's campaign so he can pocket the money as he has been doing.
Trump doesn't sacrifice for MAGA, they sacrifice themselves for him.
There is no equivalent to this anywhere on the left no matter how much you pretend otherwise. Biden is not a savior to anyone, we are thankful to him is because of the things he did for us, including saving us from a second Trump term.