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 e...