Few factors have loomed over American politics for the past decade like President Donald Trump’s sway over his base.

Lacking in broad popularity, the conventional wisdom has long been that Trump commands such intense devotion from a large swath of his base that it renders him a powerful force.

There is increasing reason to believe this conventional wisdom no longer applies.

A new Washington Post-Ipsos poll is merely the latest data point suggesting Trump’s devoted base has not only shrunk significantly, but is now historically pretty small.

The Post-Ipsos poll shows just 15% of Americans said they strongly approved of Trump — a number that translates to fewer than 1 in every 6 people. That’s a record low in the poll’s history.