In the House, Democrats are inching ever closer to impeaching President Trump. Some are even pushing for drafting articles of impeachment by Thanksgiving and, potentially, sending proceedings to the Senate by early next year. If the charges reach the upper chamber, at least 20 Republicans would have to join every Democrat in voting guilty in order to reach the two-thirds supermajority needed to remove the president from office.

So now begins the reading of the tea leaves and the careful scrutiny of every Republican senator’s statements (or silence). Will Republicans finally break with Trump? We may not know until it happens. But be forewarned — if it does happen, it will likely take us by surprise. After all, political science has shown us that big political changes often come suddenly, after long periods of stasis. Looking back, it seems like of course the Soviet Union was bound to collapse. But up until the moment it did — and remember, it fell all at once — almost nobody predicted it.