U.S. Republican presidential candidate Donald Trump speaks at a news conference at the Family Leadership Summit in Ames, Iowa, United States, July 18, 2015. REUTERS/Jim Young

Donald Trump’s surge to the front of the GOP presidential polls has occasioned not a little media attention and endless speculation as to why. You can disregard most of that speculation. The answer is simple: Trump is surging in the polls because the news media has consistently focused on him since he announced his candidacy on June 16.

Below is a graph that I made with UCLA political scientist Lynn Vavreck using social analytic tools provided by Crimson Hexagon.  These tools are devised to gather and reveal the volume and tone of media coverage on major news sites. Vavreck and I are analyzing the news coverage of presidential candidates as part of our joint work on the 2016 election.

[Trump’s attack on McCain marks a turning point for him — and the GOP]

The graph shows you how much coverage Trump got in the week before he announced his candidacy, and in the 30 days after. For comparison, there is a line for the other Republican candidates who have announced their candidacy in the past 2 months: Jeb Bush, Chris Christie, Ted Cruz, Rick Perry, Rick Santorum, and Scott Walker.


The graph shows two important things. First, Trump’s announcement generated a much larger spike in media coverage than these other candidates received. The day before he announced his candidacy, Trump received 4 percent of the media coverage devoted to these candidates. The day after, he received 31 percent.

Second, the news media’s attention to Trump hasn’t faded away, as is typical. He has consistently attracted 20-30 percent of the news coverage of these candidates. Only Jeb Bush comes close. In the month since Trump’s announcement, Trump has received 21 percent of the news coverage. Bush has received 20 percent.

[What Donald Trump was up to while John McCain was a prisoner of war]

Has this attention to Trump driven his poll numbers? Almost certainly. Think about it this way: voters don’t change their minds without new information. No one wakes up on June 17 and randomly decides on their own that Donald Trump should be the Republican nominee for president. People’s minds change because they are hearing information that they haven’t heard before.

In this case, people are being bombarded with news stories about Trump. When the news media suddenly focuses on a candidate that hasn’t previously received much coverage, Vavreck and I refer to this as the “discovery” phase of that candidate’s campaign. The resulting spike in news coverage then drives the poll numbers.

In our book on the 2012 presidential election, “The Gamble,” Vavreck and I documented this pattern over and over in 2011—for Perry, Herman Cain, and Newt Gingrich. In 2015, we’ve already seen similar, smaller surges for Cruz and Rubio after they announced their candidacies.

You can see the same pattern by closely examining Trump’s news coverage and the national polls:


Trump’s poll numbers increase only after the first spike in news coverage. Here is an apples-to-apples comparison. In a YouGov/Economist poll conducted from June 13-15—right before Trump’s announcement—Trump polled at 2 percent. In a YouGov poll from June 20-22, he polled at 11 percent.

His numbers have only increased since then. This is completely expected: Trump has received a larger-than-usual spate of media coverage and so, as Nate Cohn showed Sunday, his polling bump is larger and more durable too.

Now, it’s tempting to think that each surge is somehow the result of each candidate’s idiosyncratic appeal to Republican voters. This is what commentators often assume about Trump.

But a simpler explanation is this: when a pollster interrupts people’s lives and asks them about a presidential primary that doesn’t formally begin for months, a significant number of people will mention whichever candidate happens to be in the news these days. It’s basically a version of what’s called the “availability heuristic.” And for any causal consumer of news, Trump is very available these days.

But, as Cohn noted (and see also Andrew Prokop), this discovery phase doesn’t last. It’s followed by what Vavreck and I call “scrutiny”—in particular, scrutiny from the news media, aided and abetted by the competing candidates. (Hillary Clinton knows all about this.) This scrutiny tends to produce much less favorable coverage and, for many candidates, a permanent decline in the candidate’s poll numbers. In the primary, this is often fatal for that candidate’s campaign.

In Trump’s case, his remarks about John McCain have finally elicited strong criticisms from the other GOP contenders. Now the question is whether Trump will feel the full scrutiny of the press—which, as political scientist Matthew Dickinson argues, necessitates more than simply enabling Trump to traffic in controversy. Dickinson suggests this:

Instead, journalists should take his candidacy seriously by pressing him on the details of his policy pronouncements, and helping the public understand the differences between the public and private sector. The sooner the media begins evaluating The Donald on the details of his policies and his governing expertise, rather than on his deliberately provocative comments designed to mobilize a disaffected public, the sooner The Donald’s political bubble is likely to burst.

In other words, the media giveth, and the media can taketh away. This is what underlies the seemingly unpredictable Republican presidential primary of 2015.