How, other than an assumption that voters are too dim to remember what Mr. Romney has said across the years and months, to account for his breathtaking ideological shifts? He was a friend of immigrants, then a scourge of immigrants, then again a friend. He was a Kissingerian foreign policy realist, then a McCain-like hawk, then a purveyor of peace. He pioneered Obamacare, he detested Obamacare, then he found elements in it to cherish. Assault weapons were bad, then good. Abortion was okay, then bad. Climate change was an urgent problem; then, not so much. Hurricane cleanup was a job for the states, until it was once again a job for the feds.