The timeline for ideas going from “universally considered crazy” to “mainstream leftist orthodoxy” is something like:
Step 1: “Nobody actually believes that, stop making up caricatures of our positions.”
Step 2: “The people who believe that are a small fringe and you’re unfairly generalizing the whole left by attributing their opinions to all of us.”
Step 3: “I don’t personally believe that so you can’t make me defend it.”
Step 4: “Our candidates in swing states now endorse that as part of our platform, and any decent person must follow suit or be a racist.”
Step 5: “We are teaching that in schools and your children will fail if they don’t regurgitate it back.”
“2 + 2 = 4 is racist” is somewhere between step 2 and step 3 right now It will be interesting to check back in on this thread and others in about five years and see where we are.