Nicole Hemmer is an assistant professor at the University of Virginia's Miller Center and author of "Messengers of the Right: Conservative Media and the Transformation of American Politics." She is a co-editor of The Post's daily historical analysis section, Made by History.

When Rep. Steve Chabot (R-Ohio) had his turn to quiz former special counsel Robert S. Mueller III during the hearing Wednesday morning, he came armed with what he seemed to think was a smoking gun: that neither Glenn Simpson nor Fusion GPS were mentioned in Mueller’s report.

Most Americans no doubt shared Mueller’s apparent confusion about the line of questioning. He said he was not familiar with Fusion GPS, a private strategic-intelligence firm, and that Simpson, the organization’s founder, was outside the scope of his investigation. Yet as the hearings wore on, Republican lawmakers returned again and again to Simpson and Fusion GPS, treating them like household names. And for conservatives on a steady diet of right-wing media, they are: the linchpins of a conspiratorial witch hunt to impeach President Trump.

The GOP’s laserlike focus on Simpson, Fusion GPS, former FBI agent Peter Strzok and other bits of right-wing lore probably played well in conservative media (and, as a consequence, in the Oval Office). But it was almost certainly inscrutable to any American who is not dialed into Fox News, right-wing talk radio or conservative-leaning Facebook feeds. That has real consequences for a party that, in learning to speak to its siloed-off base, has forgotten how to reach a wider audience.

For the benefit of the Fox News crowd, Republicans raised a host of boogeymen Wednesday. In his opening statement in the House Intelligence Committee’s afternoon hearing, Rep. Devin Nunes (R-Calif.) first dismissed election interference as the “Russia collusion conspiracy theory,” then spun out a conspiracy of his own, a rush of names including Maltese professor Joseph Mifsud, Russian lawyer Natalia Veselnitskaya and — of course — Simpson, a topic he returned to during his question time. Rep. Debbie Lesko (R-Ariz.) interrogated Mueller on the number of times his report referenced the New York Times (75) and The Washington Post (60) vs. Fox News (25), as though that provided mathematical evidence of just how biased the special counsel’s team was. Rep. Jim Jordan (R-Ohio) accused the government of “spying” on the Trump campaign, and he name-checked “Halper, Downer, Mifsud, Thompson” and Azra Turk, barely pausing to suggest who they were, much less what they might have done or how their circumstances exonerated Trump.

Republicans did not always speak in an impenetrable dialect. Well into the 2000s, Republican politicians found ways to dog-whistle to the base while still addressing a broad national audience; John McCain argued in 2008 that Barack Obama would turn the IRS into a “welfare agency” but still defended Obama from fringe-motivated questions about his citizenship. But as conservative talk radio proliferated and the influence of Fox News on intra-GOP politics crystallized, Republican candidates increasingly turned their attention, and their rhetoric, toward that narrower audience. For good reason: Whenever Republican officials stopped moving in lockstep with conservative media and the base that consumed it, they found themselves enveloped in scandal — as when Republican National Committee Chairman Michael Steele was forced to apologize for criticizing Rush Limbaugh in 2009 — or out of a job, like conservative stalwarts Sen. Richard Lugar (R-Ind.) and Rep. Eric Cantor (R-Va.), who lost primary elections in 2012 and 2014 to candidates who sounded more like talk-radio hosts than mainstream politicians.

The hearings Wednesday were not the first time Fox Newspeak has been a problem for the right since that dynamic took hold. In 2014, President Barack Obama sat down for a pre-Super Bowl interview on the main Fox broadcast network with Bill O’Reilly, who at the time hosted the most-watched program on Fox News (he would be ousted three years later over multiple sexual harassment allegations). It was a huge opportunity for the network. O’Reilly’s show drew, at its peak, about 3.3 million viewers; the Super Bowl that year had 112.2 million. Even if just a small fraction of those game-watchers tuned in, it would be a substantially bigger, and different, audience for O’Reilly.

But O’Reilly used the opportunity to air a number of conservative grievances that meant very little to nonconservatives: the number of days it took to fully assess a terrorist attack on the U.S. diplomatic compound in Benghazi, Libya; an already debunked accusation that the IRS had persecuted conservative organizations; Obama’s statement that his 2008 election would play a role in “fundamentally transforming” America. Each of these were played as “gotcha” moments, but anyone watching who wasn’t familiar with the stories must have been wondering what, exactly, had been “got.”

Maybe Republicans on Wednesday, and O’Reilly back then, were trying to expose non-Fox News watchers to conservative arguments. But in neither case did they explain the underlying conspiracy theories they were gesturing to. Rather, they dropped keywords such as “Benghazi” and “Glenn Simpson” that left conservatives salivating and the rest of the country confused.

These in-group moments are great for the base, but they squander the right’s opportunity to shape a broader national debate. When it comes to major congressional hearings such as Mueller’s, that is a significant political shortcoming. That’s because such proceedings have real power (or at least, they used to). In the 1960s and 1970s, televised hearings helped remake the country in powerful ways, from ending a war to curbing government abuses.

The Fulbright hearings in 1966, for instance, empowered the antiwar movement when they raised serious questions about the origins of the Vietnam War. Though not the first congressional hearings on Vietnam, they were the first to be televised — and they had a profound effect in eroding public support for the war. The hearings could do that because the senators made their case to the public, instead of spinning off half-understood references to conspiracies about the Lyndon Johnson administration.

The same was true of the Church Committee hearings, televised in 1975. Those hearings were deliberative inquiries into the secret and often illegal actions of the U.S. intelligence community during the 1950s and 1960s, from assassination attempts to domestic spying. They involved careful investigation of wrongdoing, which, when laid out for the public, helped build support for a number of new policies, including the Foreign Intelligence Surveillance Act of 1978.

There is little chance that Republicans’ grilling of Mueller on Wednesday will inspire the same sort of change in policy or public opinion, because there is little chance that their questions made any sense to most people watching. The lawmakers were there not to investigate but to instigate, to rile up a base that had made up its mind about Mueller around the same time Trump did.

Republicans traded their big-tent strategy for a base-only one a long time ago. Their conduct at the hearings was just another sign that they have given up on reaching a broader public and will instead double down on minoritarian politics. Questions that wander off into the weeds of right-wing fever dreams are of a piece with efforts to purge voting rolls, gerrymander districts, strip power from Democratic officials and change the census. The strategy may be mysterious to the rest of us — but it’s helping the right retain its hold on power.