Only the primary? Did he switch for the general?
Still, we can all agree. Reagan can be forgiven for past mistakes. Fred can be forgiven for past mistakes and even current associations like CFR. But Mitt? No, he must be drawn, quartered and burned at the stake.
If one votes in a primary, he is a member of that party for two years in a state like MA that permits voting in the primary of one’s choice on election day. TX has the same setup. Mitt was back in the GOP in 1994 for his own race against EMK. I don’t know what he did wrong in that race.