In 2015 we witnessed an astonishing sight: by the end of the year news coverage of Donald Trump in major U.S. newspapers eclipsed coverage of every major world hotspot and the dreaded Islamic State.

At the most basic level, this reflects the American tendency to focus on domestic politics during presidential campaigns. Foreign affairs often fade from view as the presidential campaign season heats up and economic and social issues take the fore. But this year foreign policy has in fact been a major focus of the campaign, making this a less powerful effect than in most years.

More importantly, the news flow is a function of Trump’s uncanny ability to set the news agenda. This ability stems only in part from the fact that he holds a commanding lead in the polls. More critical is his tendency to make outrageous statements, tapping into anger and frustration in the electorate, which has not only stimulated outrage and concern on left and right but also discussion about what the Trump phenomenon means beyond the election itself. In December Trump appeared in twice as many stories as both Ted Cruz, his closest competitor in both the polls and coverage, and President Obama. Simply put, Trump is incredibly newsworthy given the way in which American news outlets define news and given the news Americans appear to want.

But less obviously, this pattern also reflects the long-term shrinking of the international news hole in the United States. Since the late 1980s the share of American news devoted to international affairs has shrunk by as much as half in major U.S. newspapers and broadcast television news. With occasional and temporary reversals, this trend has persisted despite increasing globalization, despite constant U.S. military intervention abroad since the early 1990s, and despite 9/11 and the war on terrorism.

Trump’s news dominance has at least three important consequences for U.S foreign policy. First, Trump’s success has clearly shifted the debate on how to confront the Islamic State. Even though Trump’s most outrageous statements about killing the wives and families of terrorists are not serious policy proposals, they have nonetheless found considerable support among the American public. And since Trump continues to lead the field, his competitors have responded by ratcheting up their own rhetoric, leading the Republican contest to take on an increasingly hawkish tone. This has also encouraged Hillary Clinton to continue to take a more aggressive stance toward confronting ISIS than she otherwise would be likely to have done. The end result is that public approval for military intervention against ISIS is at an all-time high.

Second, Trump’s rhetoric has shifted the American debate about borders and refugees in a decidedly nativist direction. Trump’s obsession with the U.S.-Mexican border early on in his campaign and his willingness to suggest extreme measures others would not ensured him a leading role in responding to the Syrian refugee crisis. In the wake of the Paris attacks, Trump’s hyperbole about the dangers posed by immigrants and refugees not only tapped into fears and frustrations of many conservatives but also pushed Republican governors and the other GOP presidential candidates to affirm extreme positions regarding Syrian refugees. At this point it will be surprising if the United States manages to take in even the 10,000 refugees President Obama originally promised and it seems extremely unlikely that the next president will suggest taking in any additional refugees.

But perhaps the most troubling consequence of the Trump phenomenon is its impact on the very quality of the foreign policy debate itself. Thanks to his popularity and the responsive chord his rhetoric has struck, Trump has legitimized a simplistic and naïve approach to dealing with the world. To listen to Trump, the United States can meet all of its challenges simply by “getting tougher” with our adversaries. In a Trump-dominated news environment the world loses its complexity and we lose the ability to ground foreign policy in a realistic and sophisticated debate about how to meet the challenges we face. 

Though election watchers remain doubtful that Trump will wind up the Republican nominee, 2016 begins with Trump in first place both in the national polls and in news coverage. And whether Trump wins a single caucus or primary, the echoes of his campaign will be felt for a long time to come.