周二晚上，前总统唐纳德·特朗普和副总统卡玛拉·哈里斯举行了他们的第一次，也可能是唯一一次总统辩论，两位候选人都希望在一场辩论中获得对对方的关键优势非常接近的比赛。根据美国公众的早期评论，哈里斯似乎脱颖而出。
截至东部时间下午1点，已有538人三国家的民意调查和一个摇摆州民意测验在辩论之后进行的。*在所有这些辩论中，认为哈里斯赢得辩论的人比认为特朗普赢得辩论的人多。平均而言，全国57%的辩论观察家认为哈里斯表现更好;只有34%的人说特朗普有。
CNN/SSRS还在辩论前对相同的受访者进行了一次民意调查，让我们比较他们在辩论前和辩论后对候选人的看法。根据他们的民意调查，哈里斯在辩论观众中的净支持率从辩论前的-11个百分点(39%赞成，50%反对)上升到辩论后的+1个百分点(45%赞成，44%反对)。然而，特朗普的净支持率几乎没有变化(从-11点到-12点)。
对哈里斯来说，这显然是个好消息——但这里有一些警告。首先，现在还早。自辩论以来，只进行了一些民意调查，我们很快就会有更多的数据来证实他们的发现或质疑他们的发现。随着观众对辩论的消化(以及与那些没有观看的人分享片段)，对辩论的看法也可能会发生变化。比如说，本周末进行的一项民意调查可能会发现一个不同于2007年11月20日晚上进行的民意调查的获胜者。
第二个警告是，即使哈里斯确实表现更好，也不一定意味着这场辩论会让她在民意调查中大幅提升。在CNN/SSRS的民意调查中，只有4%的辩论观察者说，这一事件改变了他们投票给谁的想法。另有14%的人表示，这让他们重新考虑，但不会改变主意，而多达82%的人表示，这不会影响他们的选择。
CNN/SSRS没有直接询问受访者他们支持谁，但另外两个辩论后的民意调查做了(都是由共和党公司进行或赞助的)。辩论结束后，SoCal Strategies/On Point Politics/Red Eagle Politics发现哈里斯在全国领先特朗普3个百分点，这与他们给哈里斯的2个百分点的领先优势几乎没有区别八月中。Trafalgar Group/inside advantage对七大摇摆州的辩论观众进行了调查，发现两位候选人在辩论后几乎不分上下，各有大约48%的支持率。同一样本称，在辩论之前，他们计划以1个百分点左右的优势投票给特朗普。
再说一次，这只是两项调查，所以现在就断言这场辩论没有显著推动进展还为时过早。我们建议密切关注538的平均投票率在接下来的几天里，看看未来的民意调查是否会产生任何变化。
第三个警告是，即使哈里斯做辩论后民调支持率上升，但这些优势可能会转瞬即逝。CNN民调还发现，美国人认为前国务卿希拉里·克林顿在2016年与特朗普的三场辩论中表现最佳，她在全国民调中上升前两个之后(虽然其他因素，如“《走进好莱坞》”磁带可能也考虑到了这一点)。但是，当然，竞选在最后几天变得更加激烈，克林顿最终输掉了选举。
再往前追溯，CNN民调发现，美国人压倒性地认为前马萨诸塞州州长米特·罗姆尼是2012年第一场辩论的赢家，之后他在民意测验中进步了也是。但美国人更喜欢前总统巴拉克·奥巴马在随后两场辩论中的表现，他最终获胜。
2008年和2020年，同样的候选人(分别是奥巴马和现任总统乔·拜登)被认为赢得了每一场辩论，并赢得了选举。但那些年，也有多次辩论(截至目前，哈里斯和特朗普没有再次会面的计划，尽管10月1日将有一场副总统辩论)，而且它们比今年的辩论更接近选举日。(如果不是6月份的辩论导致拜登退出竞选，本周的辩论将会是最早的大选总统辩论在现代史上。)换句话说，今年，这场辩论在选民心中淡化的时间甚至比以往更多。
最好的思考方式是什么?这听起来可能有点虎头蛇尾，总统选举在辩论前非常接近，辩论后可能会继续非常接近。
Early polls say Harris won the presidential debate
On Tuesday night, former President Donald Trump and Vice President Kamala Harris met for their first, and potentially only, presidential debate, with each candidate hoping to gain a crucial advantage over the other in avery close race. And based on early reviews from the American public, it seems like Harris came out on top.
As of 1 p.m. Eastern, 538 has collectedthreenationalpollsandoneswing-state pollthat were conducted since the debate.* In all of them, more people who watched the debate said Harris won the debate than said Trump did. On average, 57 percent of debate watchers nationally said Harris turned in the better performance; only 34 percent said Trump did.
CNN/SSRS also conducted a poll of the same respondents before the debate, allowing us to compare what they thought about the candidates before the event with what they thought about the candidates after it. And according to their poll, Harris's net favorability rating among debate watchers rose from -11 percentage points (39 percent favorable, 50 percent unfavorable) before the debate to +1 point (45 percent favorable, 44 percent unfavorable) after it. Trump's net favorability rating, however, barely changed (from -11 points to -12 points).
That's all obviously good news for Harris — but there are a few caveats here. First of all, it's still quite early. Only a few polls have been conducted since the debate, and we'll have more data very soon that will either confirm their findings or throw them into doubt. It's also possible that perceptions of the debate will evolve as viewers digest it (and as clips get shared with those who didn't watch). A poll conducted, say, this weekend may find a different winner than a poll conducted the night of.
The second caveat is that, even if Harris did turn in the better performance, that doesn't necessarily mean that the debate will give her a significant boost in the polls. In the CNN/SSRS poll, only 4 percent of debate watchers said the event changed their mind about whom they were voting for. An additional 14 percent said it made them reconsider but not change their mind, while a whopping 82 percent said it did not affect their choice.
CNN/SSRS did not ask respondents directly whom they were supporting, but two other post-debate polls did (both conducted or sponsored by Republican firms). SoCal Strategies/On Point Politics/Red Eagle Politics found Harris leading Trump nationally by 3 points after the debate, virtually indistinguishable from the 2-point lead they gave Harris inmid-August. And in their survey of debate watchers in the big seven swing states, Trafalgar Group/InsiderAdvantage found the two candidates virtually tied after the debate at about 48 percent apiece. The same sample said that, before the debate, they were planning to vote for Trump by around 1 point.
Again, this is only two surveys, so it's far too early to make any pronouncements that the debate didn't significantly move the needle. We recommend keeping an eye on538's polling averagesover the next several days to see if future polls produce any movement.
The third caveat is that, even if Harrisdoesrise in the polls after the debate, those gains could be fleeting. CNN polling also found that Americans thought former Secretary of State Hillary Clinton turned in the best performance in all three of her debates with Trump in 2016, and sherose in national pollsafter the first two of them (although other factors, such as the"Access Hollywood" tape, likely factored into that as well). But, of course, the race tightened in the final days and Clinton went on to lose that election.
Going further back, CNN polling found that Americans overwhelmingly considered former Massachusetts Gov. Mitt Romney the winner of the first debate in 2012, after whichhe improved in the pollsas well. But Americans preferred former President Barack Obama's performance in the two subsequent debates, and he eventually won.
In 2008 and 2020, the same candidates (Obama and now-President Joe Biden, respectively) were perceived to have won every debate and also went on to win the elections. But those years, there were also multiple debates (as of now, Harris and Trump are not scheduled to meet again, although there will be a vice-presidential debate on Oct. 1), and they happened much closer to Election Day than this year's debate. (If not for the June debate that led to Biden's withdrawal from the race, this week's debate would have been theearliest general-election presidential debatein modern history.) In other words, this year, there is even more time than usual for the debate to fade in voters' minds.
The best way to think about it? As anticlimactic as this may sound, the presidential election was very close before the debate, and it will likely continue to be very close after it.
