In Iowa, Buttigieg seeks Trump voters. He may need more Democrats.

In conversations with rural voters, the mayor of South Bend, Indiana, exudes both smarts and folksiness. Many say they want a candidate who will “look out for the common man.” But plenty of Iowans still don’t know who he is.

Gary Kupferschmid managed to snag the autographs of five presidential candidates in just three hours at the Iowa State Fair this month, adding to a hefty collection that includes Jimmy Carter, George W. Bush, Barack Obama, Hillary Clinton, and Donald Trump – the last of whom got his vote in...