As the aphorism goes: Another year older, another year wiser, another year closer to death. The passage of time and the mercy of presidential term limits means that 2019 brings us closer to the end of the Trump era. The coming year will determine whether that era ends in a bang or a whimper.

Will Democratic control of the House and the ongoing Mueller investigation dovetail into real political consequences for Trump’s inglorious track record of graft and dissembling? While Republican control of the Senate makes impeachment and removal a pipe dream, 2019 will see an acceleration of new subpoenas, new disclosures, new investigations, and new convictions that may well change the political calculus within the Republican Party. The conditions may be ripe for a primary challenge — some ego-driven and principled conservative (Paul Ryan? John Kasich? Nikki Haley? Mike Pence?) will rise to confront Trump’s cult of personality.

What a conservative challenge to Trump looks like in 2019, and what a contested Republican primary looks like in 2020, would ultimately be determined by neither Trump nor the Republican Party.

Indeed, there’s an elephant in the Republican Party — and it’s not the one you think. If the Reagan presidency was the crowning achievement of the post-war conservative movement, the decades since have seen that movement eclipsed by a commercially viable conservative mediasphere with power and motivations all its own.

Its foundations were built by talk radio hosts like Rush Limbaugh beginning shortly after the Reagan FCC ended the “fairness doctrine” broadcast requirements in the late 1980s. By the mid-1990s, Fox News arrived on the scene, with its “fair and balanced” answer to putative liberal media hegemony. The past decade has seen a quickening of the conservative mediasphere, with proliferating online outlets — from Glenn Beck’s The Blaze, to Breitbart, to The Daily Caller — not to mention successful social media entrepreneurship of figures like Ben Shapiro and Tomi Lahren.

For its part, the Republican Party has largely avoided publicly acknowledging its subordinate status within the broader constellation of conservative media institutions. The 2012 Republican autopsy report, commissioned after Romney failed to defeat Obama, made no reference to any part of the right-wing mediasphere within whose constraints the party’s candidates are increasingly forced to operate. The report’s section on “Friends and Allies,” for example, describes pertinent third-party groups as consisting of “advocacy organization to think tanks to political action committees to SuperPACs or 501(c)(4) organizations” — no discussion of the increasingly outsized role played by outlets of conservative news and commentary.

Scholars and progressive media critics, on the other hand, have often depicted the conservative mediasphere as a powerful monolith. David Brock famously called it a “noise machine.” At the outset of their pathbreaking work on the conservative “echo chamber,” Kathleen Hall Jamieson and Joseph N. Cappella predicted that if the conservative media establishment of the time (Rush, Fox, and The Wall Street Journal opinion page) “were confronted by a serious Republican presidential contender whose proposals and past deviated from the Reagan doctrine, they would marshal against the candidacy.” At the time of publication, Mike Huckabee’s failed 2008 presidential run seemed to confirm their claims as conservative media challenged his bona fides. But by later that year, Fox had hired Huckabee, giving him a show of his own.

By the 2016 Republican primaries, the “echo chamber” seemed unable and unwilling to police Trump’s far more egregious deviations from the fusionist conservatism that Reagan embodied. The National Review’s attempt at launching a “Never Trump” movement quickly fizzled, while the more widely circulated (not to mention more paleoconservative and supportive of white nationalists) Breitbart threw its full support behind Trump’s candidacy. As Yochai Benkler, Robert Faris, and Hal Roberts have compellingly documented, by 2015 Breitbart had emerged as a crucial and influential node within the broader conservative mediasphere. The success of an ardent and widely shared pro-Trump site forced Fox News to guard its right flank.

The Trump presidency has resulted in further thematic, and to some extent ideological, consolidation within the conservative mediasphere around Trump and his policies. Fox has rebuilt its primetime lineup with Trump acolytes and apologists. Right-wing publisher MediaDC gave the ax to neoconservative The Weekly Standard while expanding the more Trump-loyalist Washington Examiner.

What happens to the conservative mediasphere when it loses its current center of gravity?

Trump has largely championed the ideas of long-beleaguered paleoconservatives, but neoliberal conservatives, libertarians, neoconservatives, and fusionists will all be vying to control the post-Trump Republican Party. Without Trump as its lodestar, the conservative mediasphere is likely to experience a period of fragmentation as well — competition for right-wing audiences and clicks will foster ideological sorting as different sites will seek to establish their niches and advance these competing conservatisms.

Of course, it’s also possible that some other conservative figure will quickly step in to fill the impending Trump power vacuum. Such a figure could stave off conservative mediasphere fragmentation a bit longer.

But even if that happens, media critics, journalists, and journalism scholars would be wise not to take a monolithic conservative mediasphere for granted — to acknowledge that unity of messaging among discrete conservative media outlets is historically contingent. The more we can learn about the political, ideological, and commercial imperatives that produce conditions of unanimity within the conservative mediasphere, the better we’ll understand its component parts, and the challenges it presents for professional journalism.