Does this remind you of anything else in U.S. history

 

A man who ran formerly with Trump, as his VP candidate in two successive elections, is now running against Trump for the Republican nomination. 

It is reasonable to ask: has anything like this happened in US history before? Well, nothing VERY much like this. Something similar would have happened if Theodore Roosevelt and William Howard Taft had shared a ticket in 1904. Then one could say, "Four years later, TR passed the baton to Taft and went into retirement. Four years after THAT, Roosevelt challenged Taft for the nomination of the Republican Party, and ended up running against him in the fall election as well."

Except it didn't happen that way. TR's veep was the eminently forgettable Charles Fairbanks. Taft was that administration's Secretary of War. For that he gets the memorialization I have just given him by pasting his portrait at the top of this entry. 

Another comparison that comes to mind: Henry Wallace's falling out with another Roosevelt, and eventually his campaign against Truman from the left, in 1948. If Roosevelt had lived long enough to run for a fifth term in 1948, and Wallace had created a third party to try to undermine that fifth campaign, THAT would have been an analog to what is happening now.  

Wallace was FDR's vice president for his third term. As that third term drew to a close, it became obvious that Wallace disagreed fundamentally with Roosevelt about what the post-war world would look like. Wallace believed that the alliance with the Soviet Union should be continued into peacetime and Stalin, along with his successors, should have a central part in the postwar order. Roosevelt believed (as, for example, the Bretton Woods talks demonstrated) that the U.S. and its western allies should build a post-war order themselves, and keep the Soviets at arm's length to the extent possible. Truman's policy of "containment" was much closer to FDR's own thinking than what Wallace had in mind.   

Through some fairly complicated maneuvering, Roosevelt dropped Wallace from his ticket for his fourth campaign, putting Truman in his place. Only months later, Roosevelt died, and Wallace contended with Truman to be, in effect, his political heir. 

If we think of Roosevelt and Truman as a compound personality, we can think of Wallace as Pence at this moment, contending for the top job in 1948. 

Again, not a great analogy. This bit of history not only doesn't  repeat anything else. It doesn't even have any very good rhymes.