The past isn’t always prologue — but this week it might turn out be. That’s what can happen when two bitter rivals for the White House meet for a rematch on a debate stage and their positions on many of the major issues are well-established. Even so, President Joe Biden’s and former President Donald Trump’s face-off this week — expected to be one of the most consequential moments so far of campaign 2024 — is almost certain to surprise us in some way. Debates almost always do. CNN Opinion...