Ever since Donald J. Trump’s stunning victory in 2016 — when he lost the popular vote by almost three million votes but still triumphed with over 300 electoral votes — many who follow politics have believed Republicans hold an intractable advantage in the Electoral College.

But there’s growing evidence to support a surprising possibility: His once formidable advantage in the Electoral College is not as ironclad as many presumed. Instead, it might be shrinking.

According to The New York Times’s polling average, it does not seem that Kamala Harris will necessarily need to win the popular vote by much to prevail.

The simplest way to measure the advantage in the Electoral College is to take the difference between the national popular vote and the vote in the “tipping-point” state (the state that puts one candidate over the top in the Electoral College). Right now, Vice President Harris leads the polling in the national vote by 2.6 percentage points, and leads Wisconsin — the current tipping-point state — by 1.8 points, which makes Mr. Trump’s advantage less than a point.

By this measure, Mr. Trump’s advantage is only around one-fifth as large as it was four years ago, when he fared 3.8 points better nationally than in Wisconsin (the tipping-point state in 2020).