Despite frequent claims over the decade that tax cuts for the rich were morally reprehensible, the Democrats did not allow the tax cuts to automatically expire,

Despite frequent claims over the decade that tax cuts for the rich were morally reprehensible, the Democrats did not allow the tax cuts to automatically expire, extending them for two years in the lame duck session of Congress, and then most were made permanent two years later before they should have expired again. Isn't that the opposite of "undoing legislation"?