No election in decades has offered more cause for humility among political prognosticators than the 2016 presidential race, now just weeks from its first real contests.

A candidate dismissed as preposterous from the outset, celebrity businessman and GOP front-runner Donald Trump, has commanded center stage since July. Jeb Bush, the early smart-money pick to be the Republican nominee, has gone nowhere. The unbeatable Hillary Clinton is struggling in New Hampshire. And no one has any firm idea what this race will look like come early fall.

Still, there are some certainties, or at least near-certainties, all of which serve to highlight the total weirdness of the 2016 campaign.