Bernie Sanders, Donald Trump, Ben Carson (Reuters, AP, Bloomberg)

At the beginning of this year, the Annenberg Public Policy Center at the University of Pennsylvania sponsored a focus group in the Denver suburbs composed of a dozen adults — Republicans, Democrats and independents. Looking back almost nine months later, the two-hour discussion proved to be a prescient guide to the surprising politics of 2015.

For any conventional politician paying attention, what was said there should have been unnerving. The name Donald Trump was never mentioned, nor was that of Ben Carson or Bernie Sanders. But the sentiments expressed that evening help explain why those three candidates are in the forefront of the political conversation on this Labor Day weekend.

The participants made it clear that they were fed up with politics as usual. They were harsh in their judgments about most traditional politicians, the political establishment and the way Washington works. They had no particular appetite for a clash-of-dynasties presidential campaign pitting a Bush against a Clinton.

They were especially critical in their assessments of Jeb Bush. They were tepid toward Hillary Rodham Clinton, although judgments fell more predictably along partisan lines. The participants longed for someone who seemed different and who they believed understood their lives. The name Elizabeth Warren, the populist senator from Massachusetts, sparked positive comments, even from some of the Republicans.

When the conversation was all over, pollster Peter Hart, who conducted the session, summed up what he had heard. “The political classes told us it’s going to be Bush against Clinton, but these people are hundreds of miles away from that choice,” he said. “Essentially what they’re telling us is, ‘I don’t trust these people. They’re part of an establishment that I don’t like.’ ”

Republican presidential candidate Donald Trump released this video via social media demanding an end to the Clinton and Bush dynasties. (realdonaldtrump/Instagram)

This was in no way a scientifically drawn cross section of the population, and yet the collective voices of the dozen adults were an early manifestation of what has played out in the months since.

Bush has had an extremely rocky time, whether because of his family name or in spite of it. He was able to gather huge sums of money from the political establishment for his super PAC. But he has failed so far to truly strike a chord with rank-and-file Republicans. Most telling perhaps is the degree to which Republicans have a decidedly mixed impression of him. That is evident in national and state polls.

Clinton has held up better than Bush, but she has not had a good summer either. There are no victory laps being run at her headquarters in Brooklyn, only the grim recognition that their predictions of a competitive nomination contest have come to pass.

Clinton is better-liked among Democrats, by far, than Bush is among Republicans, and she is still the favorite to win the nomination. But perceptions of her honesty and trustworthiness have taken a beating. Still struggling to make a genuine connection with many voters, her image has been deflated by months of controversy, despite everything she and her campaign have tried to do in response.

Her troubles stoke fears about general election vulnerabilities and calls for Vice President Biden to jump in, though he remains emotionally rocked by the death of his son Beau.

Whether out of pride, stubbornness or something else, Clinton has misread legitimate concerns about her private e-mail server and what they say about her. As a result, she has badly mishandled the issue. She has treated it almost solely as a legal problem (which it could be) rather than a political problem — just as she seemed to approach the promotion of her memoir of her tenure as secretary of state as a book tour rather than the start of her presidential campaign.

Democratic presidential candidate Hillary Clinton sat down for an extended interview with MSNBC's Andrea Mitchell. Here's what she had to say about her possible 2016 competition, and the e-mail controversy that won't die. (Gillian Brockell/The Washington Post)

So it has been a difficult year for the dynastic duo. Their advisers offer similar diagnoses and prescriptions: It’s a long campaign and there’s no need to panic. People still don’t know them well enough yet — and when they do, things will look better.

Meanwhile, the political outsiders have been embraced with unexpected enthusiasm. That is especially true in the Republican race, but the success of Sanders shows that there is something broader afoot in the way voters are responding to candidates.

When Reince Priebus, the chair of the Republican National Committee, has to go to Trump Tower to get the candidate to sign a pledge to support the party’s nominee for president, as he did on Thursday, it’s clear that Trump is in a special place compared to the other 16 Republican hopefuls.

Clinton says half-jokingly and half-mockingly that the party of Lincoln is now the party of Trump. The Priebus pilgrimage last Thursday suggests that Clinton’s characterization is hardly fanciful. At this moment at least, the Republican Party is being played by Trump. Party leaders also know that, whether inside the tent or outside, Trump is, as Newt Gingrich put it recently, political nitroglycerin.

Carson, the retired neurosurgeon, is the anti-Trump in terms of style and demeanor — soft-spoken and calming. Unlike Trump, he is far more consistently conservative in his views. What they share is that neither speaks the language of a conventional politician.

Since the first GOP debate last month in Cleveland, Carson has seen his stock rise, even as some of the Republican officeholders in the race have sagged. He still generally trails Trump, but no one has a better favorable rating in Iowa than Carson, according to the Des Moines Register-Bloomberg News survey, or a net favorability rating nationally, according to the latest numbers from Gallup.

A Monmouth University poll released last week tested hypothetical head-to-head matchups between Trump and many of the other GOP candidates — anticipating the eventual shrinking of the GOP field once the primaries begin. Trump demolished every one of the others tested — Bush, Marco Rubio, Chris Christie, John Kasich, Ted Cruz, Carly Fiorina, Scott Walker and Rand Paul. Everyone, that is, except Carson, who had a double-digit advantage over Trump.

In the Democratic race, Sanders has taken the energy that was there earlier waiting for Warren and run with it. Few people think an aging socialist can become president, but few thought that by the end of August he would be ahead of Clinton in some polls in New Hampshire or closing in on her in Iowa.

His relentless focus on income inequality and the role that billionaires play in bankrolling super PACs captures the dissatisfaction with the political status quo that the Denver focus group participants were expressing. Clinton talks about many of those same issues, but not in the way Sanders does. After all, the former senator from New York is closer to Wall Street by far than the Vermont senator.

The campaign enters a new phase beginning next week. Soon, the airwaves will begin to fill with ads, positive and negative. There will be more debates and more engagement, all of which will shape perceptions of strengths and weaknesses. Voters’ loyalties will no doubt change. For Trump and the other outsiders, this presents fresh challenges, with no certain outcomes.

Trump, who has kept fact-checkers working overtime, reminded people of his limitations as a possible president last week when he stumbled over foreign policy questions during an interview with conservative radio talk show host Hugh Hewitt. To this point, missteps have not slowed his campaign. That might not be a permanent condition.

Still, the traditional candidates cannot be secure in waiting for the voters to come to them. If Bush and Clinton and the others succumb to thinking that the world has spun out of its axis this summer and will eventually return to a familiar normal, they could be missing part of the message of this strange year. Something is stirring and they had better be ready.