“In other words, nothing “happened” to Walker. His weaknesses as a national candidate were there for all to see, but most Republicans preferred not to see them until Walker made them impossible to ignore. Many of his fans assumed that Walker’s poor grasp of foreign policy issues would be remedied over time, but instead he has just adopted the most hard-line positions he could find with no sign that he has thought seriously about any of them. It is often said that he has been hurt most by Trump’s presence in the race, but that is mostly because he has responded to Trump’s challenge in the most ham-fisted and clumsy way possible.”