How Much Political Experience Does It Take to Be Elected President?

You’ve never seen a House member elected president. Neither have your parents — nor, in all likelihood, their parents. The last time it happened, there were 38 states and electricity was a novelty.

The year was 1880, the congressman James Garfield. The 14 decades since are littered with the failed campaigns of House members who thought they could replicate his feat.

But that hasn’t stopped six more from trying this year, a full quarter of the Democratic field.

As for what Mayor Bill de Blasio of New York, the most...