字幕表 動画を再生する 英語字幕をプリント Let's talk about the polls and whether we can trust them to pick the next US president. The president is behind — and behind by a lot. Most national polls have Joe Biden with a lead over Donald Trump. Sound familiar? Polls showing Hillary Clinton ahead. This is unheard of in recent presidential politics. Just ask Hillary Clinton how that turned out for her. So if polls can't predict a winner why are there so many of them? Can we trust them? And while we're talking predictions will Trump win again? When it comes to picking the winner of a presidential race Allan Lichtman thinks opinion polls are a waste of time. He says they're snapshots, not crystal balls. Who's Allan Lichtman? Only the guy who's predicted every winner since 1984. That's nine US presidents in a row. He predicted Ronald Reagan's win nearly two years before the vote. He called Barack Obama's re-election in 2012 when many people thought the race was too close to call. And against almost all the polls he picked Donald Trump in 2016. So who is Lichtman picking for 2020? We'll get to that in a bit. But first let's talk about the polls. There are national polls, state polls and a whole lot of other polls. And they all do things differently. US broadcasters like CNN and Fox News do their surveys over the phone. Associated Press and the Pew Research Center recruit people offline but their surveys are online. Pollsters might ask questions like: Would you say that your choice of Trump is more a vote for Trump or more a vote against Biden? But there are many other factors that can influence the results. Things like who paid for the poll because that could bias the pollster. How were participants chosen? Where are they from? And that's where something called weighting comes in. It's a calculation used by pollsters to make sure their sample is representative of an area, state or the whole country. They adjust the sample for things like education, age and gender. So those are the kinds of things pollsters try to do to stay as accurate as possible. But in 2016 a lot were off the mark. Back then some said Clinton's chances of winning were high. But she didn't win. That's because while Clinton got more votes overall what's called the popular vote she lost the Electoral College, which is the voting system used to decide the presidency. That rarely happens. And the pollsters didn't see it coming. So how'd the polls get it so wrong? Well one of the biggest mistakes in 2016 happened with state polls. The Pew Research Center says there were too many cheap-and-fast polls and too many college-educated people were interviewed. On Election Day two things happened. First, there was a higher turnout in rural counties and a lower turnout in urban ones. That helped Trump. And second, there were a lot of undecided voters who chose Trump at the last minute. But some of them didn't even get that far. Research suggests that in 2016 a lot of people were discouraged from voting because according to the polls Clinton looked like a shoo-in. Pollsters say they've learned from their mistakes. And they better hope so because the combination of Clinton's loss and Trump's win convinced a lot of people that polls are just junk. But two years later the polls for the US midterms helped repair some of the damage. And now the polls are back with a vengeance. New polling on the 2020 presidential race. Former vice president Joe Biden with a lead over President Trump. President Trump behind in two states ... The poll also shows Biden with a 10-point lead … But David also says a lot can still change. And he's not alone. That doesn't mean we can't ever trust polls. There are ways you can verify them. And don't just read one poll. Read many. It's like getting more than one opinion. The accepted wisdom is that polls do a good job of taking the pulse of public opinion. Are people worried about losing their jobs? Do they care about racial inequality? What about the pandemic and their health? So let's bring back Allan Lichtman and find out whether he thinks Trump will win again. He's created what he calls the 13 keys the keys to the White House. If Trump loses out on six or more Lichtman says the president is gone. So, No. 1 is midterm elections. The Republicans in 2018 did badly so that's strike one against Trump. No. 2 is party nomination. He didn't have to fight for it so score one for Trump. Three is incumbency. Obviously that's a win for Trump. Any third parties running? Nope. He gets another key. The short-term economy? Well, the US is in a recession. Bad for the president. Outlook for the long-term economy? Also not good. Any major policy changes from the previous administration? There've been plenty. Another one for Trump. Key No. 8 is social unrest. And race relations in the US are awful so Trump loses out there too. Then there's scandal. Trump takes key No. 10: No foreign policy or military failures. But he loses out on No. 11 which is foreign policy or military successes. The next one asks whether the incumbent Donald Trump is inspirational and charismatic. According to Lichtman he is a flashy showman but he only appeals to a narrow slice of the electorate. And finally, is the challenger Joe Biden charismatic and inspirational? Lichtman isn't convinced. So will Trump remain in the White House? According to Lichtman the president has lost out on seven of 13 keys. So he's pretty confident — but there's a catch. Lichtman says two things could throw out his prediction: Russian hackers, and what he calls voter suppression by the Trump administration. And 2020 is far from an ordinary election year the pandemic and the ruined global economy made sure of that. This race is still a tough one to call … no matter what the polls say. The original interview with Allan Lichtman was conducted by our colleagues at The Take, which is an Al Jazeera podcast. You can listen to their episode about polls wherever you get your podcasts. I'll see you next week.