Donald Trump answers a question at the Republican presidential debate Thursday in Cleveland. (Brian Snyder/Reuters)

Here, I think, is a common view of this year’s presidential primary, courtesy of the Washington Post’s Philip Rucker:

This has become the summer of the political outsider, as a cast of interlopers upend and dominate the presidential nominating process in both parties.

The surging candidacies of Donald Trump and Bernie Sanders are fueled by people’s anger with the status quo and desire for authenticity in political leaders. Across the ideological spectrum, candidates are gaining traction by separating themselves from the political and economic system that many everyday Americans view as rigged against them.

Support for Ben Carson and Carly Fiorina is also attributed to similar sentiments.

Is there evidence for this?  To date, I’ve seen little.  What I’ve seen is a surge for candidates like Trump, evidence of voters’ dissatisfaction with the status quo, but nothing necessarily linking the two.

Now here is some evidence, although I’m going to suggest you take it with a grain of salt.

The latest Washington Post/ABC News poll included two questions that gauged voters’ views of the political system. The first was “Do you think most people in politics can or cannot be trusted?” The vast majority, 72 percent said “cannot be trusted,” and 48 percent felt that way strongly. This is no surprise, given generally low levels of “political trust.”

The second question was “Do you think the current political system in the United States is basically functional or basically dysfunctional?” Most people, 64 percent, said “basically dysfunctional” and 46 percent felt that way strongly.

These two questions may not be tapping “anger,” exactly, but they do get at people’s dissatisfaction and sense of separation from the political system.  Let’s combine these two questions into an overall measure I’ll call — for lack of a better term — “dissatisfaction with politics.”

The graph below shows how dissatisfaction is correlated with support for Trump and Sanders, to a lesser extent Carson, but not Fiorina.  Here I’m comparing people who exhibited below-average and above-average levels of dissatisfaction (acknowledging that the average person is dissatisfied in absolute terms).

Among people who are more dissatisfied, support for Trump and Sanders is clearly higher (16 points and 14 points, respectively).  The difference for Carson is smaller (about 5 points).

This correlation holds up after accounting for other factors.  Compared to supporters of any of the GOP candidates who have held elective office, Trump supporters are more dissatisfied with politics — even after accounting for GOP voters’ gender, age, level of formal education, their self-reported ideology on a liberal-conservative scale, and whether they identify as evangelical Christians.

In fact, dissatisfaction is the only one of these factors associated with Trump support.  This is yet again further proof that support for Trump is not about ideology and it’s not necessarily, as some have claimed, about the “blue-collar” or “populist” politics of voters without college degrees.

For Sanders, many now-familiar factors are associated with support for him. Compared to supporters of Hillary Clinton or any other Democratic candidate, Sanders supporters are younger, more liberal, better educated, more likely to be white, and more likely to be men. But even after accounting for these factors, Sanders supporters are more dissatisfied than Clinton supporters.

Now here comes the big caveat, and it’s why I said “grain of salt” above and why I keep saying “correlation” throughout. Does political dissatisfaction actually cause people to support candidates like Trump or Sanders? It’s hard to know.

Making things even more complicated is the fact that these two questions measuring dissatisfaction came very soon after questions asking Democrats and Republicans which candidate they prefer in the primary.  So it’s possible that their stated levels of satisfaction or dissatisfaction are to some extent rationalizations of their candidate preferences rather than reasons for those preferences.

Because of this possibility, I don’t even examine a subsequent question in this poll asking whether people would like the next president to be “someone with experience in how the political system works” or “someone from outside the existing political establishment.” Your answer to that question could be even more clearly a consequence of having just said that you supported Trump.

Here’s another important caveat. People who are dissatisfied with politics may be more attracted to Sanders, Carson, and Trump. But their dissatisfaction cannot actually explain why these candidates have experienced surges.

After all, people’s dissatisfaction with politics has been a chronic feature of the past several years — as you can see here. So it’s not as if there has been some sudden increase in dissatisfaction that’s helped Trump or Sanders.  You can’t explain something that has changed — in this case, Trump’s or Sanders’ poll numbers — with something that really hasn’t changed.

Instead, the key driver, as I’ve argued repeatedly, is media coverage. You need a change in the information that voters are getting in order for their preferences to change. What the potential impact of political dissatisfaction signals is which voters might be more susceptible to wall-to-wall coverage of Trump or the increasing coverage of Sanders and Carson.

Of course, that voters unhappy with our politics are drawn to Trump or Sanders today doesn’t mean they will be in a week or a month or when the actual caucuses and primaries get underway.

Thanks to the Post’s Scott Clement for sharing data.