Just ask Mitt Romney, Dole or John McCain: You don’t have to win over the whole of the GOP base, but you do need a big enough share of conservatives that when they are added to the more moderate voters already on your side, you have enough to win (Reagan did this in reverse: He had the base largely locked up and then worked assiduously to reassure the moderates).
This is a lesson many on the right seem incapable of learning, which is why every primary season we see half a dozen right-wingers battling for the title of “purest conservative,” while the moderate candidates fight merely for the title of “conservative enough.”
And that’s Jeb Bush’s problem. He’s antagonized the base on hot-button issues such as immigration and the Common Core curriculum, without trying to persuade anyone he’s conservative enough. He even presented Clinton with an award on the eve of the first anniversary of the Benghazi attack.
Reasonable people can debate his stances, but trust me when I say the base feels decidedly unwooed.