Charlie Cook: “The age-old debate over whether it is better to nominate a candidate who can motivate the party base or one who reaches into the middle, appealing to independent and other swing voters, is presenting a choice of walking or chewing gum—you have to do both. Where these things come into conflict is that the issues that most motivate the base, whether within the Democratic Party or the Republican Party, are often ones that grate on the nonideological, or at least less ideology-driven, voters in the middle.”
“Trump has clearly picked the base-motivation model, effectively conceding the middle ground to Democrats—if they choose to take it.”

