Donald Trump’s rise triggered a debate about the so-called alt-right, how best to define it, and its role in the American political theater. Broadly speaking, two poles dominate that debate, as most of the public focuses its fleeting attention elsewhere.

One side defines the alt-right broadly enough that it encompasses large swaths of the Republican Party, the conservative movement, and Trump supporters. And it regards all three groups as discredited by the alt-right’s racist ideology.

The other side defines the alt-right narrowly, so that it constitutes a tiny, marginal group of fringe ethno-nationalists who wield almost no influence in the Republican Party, the conservative movement, or the pro-Trump coalition.

Last week I heard an alternative theory. As David French sees it, the alt-right is a tiny group, and its ideology differs significantly from the mainstream of the Republican Party. Yet the alt-right has had a significant, negative influence on conservatives, he contends, through its tactics.

Read: Trump’s white-nationalist pipeline

“The alt-right is a combination of ideology and tactics,” French said Friday at the Aspen Ideas Festival, co-hosted by the Aspen Institute and The Atlantic. “Ideologically, the alt-right is white nationalist. It is post-constitutionalist. And it is often quite pagan … Nobody knows how big it is … if it numbers in the thousands or the tens of thousands … It’s not a huge number of people.”