The most important election of the year, apart from the one occurring on November 8, takes place tomorrow. That’s when Speaker of the House Paul Ryan goes up against the vice president of a water filtration company, Paul Nehlen, in the first serious primary challenge that Ryan has faced in the 18 years since he was elected to Congress.

The odds for Nehlen are long. Of nearly 5,000 primaries held between 1992 and 2012, only 31 challengers toppled the incumbent. Nehlen also seems a little goofy, if a campaign ad is anything to go by. He has a much smaller bank account, too, with about $175,000 in cash on hand as compared to Ryan’s nearly $10 million. And one poll has him getting creamed.

Nehlen’s competence and leadership ability, however, are beside the point. This is a national fight about the direction of Republican politics, and outsiders like Ann Coulter and Michelle Malkin have shown up to campaign for Nehlen, while numerous conservatives, including icon Phyllis Schlafly, have offered their support. What’s more, we have been here before. In 2014, former House Majority Leader Eric Cantor went down to defeat in a primary against David Brat, a college professor who had spent only $200,000 in comparison to Cantor’s $5 million. It should have been a warning to Republicans nationwide that voters didn’t like Cantor’s pro-trade, pro-bailout, pro-immigration reform record. But few wanted to hear the lesson. Instead, the party put its hopes behind Jeb Bush.

At the time, Cantor’s defeat perplexed editorial writers. The New York Times editorial board decided that the election upset demonstrated that the “forces of political nihilism” were “on the rise” among Republicans, who viewed even “far right” as “too moderate.” Absent was any acknowledgement of Brat’s skepticism of Wall Street (most recently reflected in his opposition to a control board for Puerto Rico on the grounds that it would turn “free citizens into subjects”) or donor-class interests, in general. To see anything more interesting in the situation would have required open eyes rather than a stubborn narrative and a tap of the snooze bar.

We can see more clearly now that Brat’s victory was an early battle in a civil war among Republicans that will come into full view on Tuesday. At stake was whether the party should adopt the pro-trade, pro-immigration stance of Paul Ryan or the trade-skeptical, immigration-skeptical stance of Donald Trump, the two candidates that now have our attention. Former president George W. Bush recently placed himself, unsurprisingly, on the Paul Ryan side of the divide, delivering remarks warning against “isolationism, nativism, and protectionism.” Paul Nehlen has, of course, taken the Trump side of the divide, attacking Ryan as a “soulless globalist.”

But Bush’s stance, most notably, is not quite Republican, per se. Establishment Democrats and Republicans both favor high levels of military intervention, trade, and immigration, even when it puts them out of sync with their own voters. Democrats pretend to be against our trade deals, until they’re elected. Republicans pretend to be against legalization of people here illegally, until they’re elected. Both claim to hate war, but neither seeks to reduce the military presence of the United States on the world stage.

“Populism is a tough fit for a party that was traditionally the refuge of moneybags, but the workings of supply and demand have made such a makeover plausible.”

This consensus has long defined what’s considered to be the sensible center. A Republican who hews to prevailing opinion on trade and immigration and war, yet otherwise engages in opportunistic gamesmanship, is called a “moderate.” The other sort of Republican—the one that rejects the consensus and actually tries to be more consistent, even if it can seem obdurate—is called “extreme.”

As a result, more and more voters find themselves occupying the unlikely ground of “extremism” during this election cycle, which attracts them to Bernie Sanders or Donald Trump. If these voters go for Republicans, it’s often because Democrats repel them on social issues in the culture war. If they go for Democrats, it’s often because Republicans offer nothing but donor-class priorities. (Republicans are also worse when it comes to hypocrisy, supporting fiscal irresponsibility, and nation building and bank bailouts when their guy is in office and suddenly deploring them when the other guy is in office.)