The Trump tape controversy might be different from past scandals, but it shares similarities to those he has recovered from. Polls show the Republican falling further behind in the presidential race. And heavy weighting can give one person a significant impact on a poll’s results. This is HuffPollster for Thursday, October 13, 2016.

THE LATEST TRUMP SCANDAL MIGHT STICK – Amy Walter: “Over the last year we’ve witnessed a familiar pattern: Trump does or says something controversial/contentious/reprehensible (think: attacks on Judge Curiel and the Khan family), his poll numbers plummet… Then, like clockwork, the race stabilizes…. But, with less than a month out from the election, with voters actually voting and with Trump seemingly more focused on an all-base, all the time strategy, is the pattern going to be broken?… How it’s different: … There have been two polls released since the audio tapes became public. Both of them show Trump taking a pretty serious hit, especially with the kind of swing voters he needs to keep the race competitive: namely independents, women and college educated voters….  People are already voting…. A dip in enthusiasm for Trump and an increase in support and enthusiasm for Clinton now translates to actual votes…. How it’s the same: Hillary isn’t any more popular today than she was in September…. Strategists for both parties say it’s too soon to know if Trump’s troubles are leaching down to the congressional level…. However, both sides believe Trump is becoming more of a liability to GOP down ticket candidates than he was earlier this fall.” [Cook Political Report]

CURRENT HUFFINGTON POST FORECAST – Hillary Clinton has an 90.7 percent chance of winning the presidential election. Republicans have a 67 percent chance of keeping the Senate. [Presidential forecast, Senate forecast]

THE LATEST POLLS AREN’T GOOD FOR TRUMP – Polls are still catching up to the latest campaign events, but the trend looks bad for Donald Trump. New releases show Trump trailing in most states, even though some of the polls were in the field before last Friday’s revelations, and all were completed before further sexual assault allegations against Trump began coming out on Wednesday. A national online poll from Insights West, conducted on Monday and Tuesday, shows Clinton at 42 percent, Trump at 37 percent, Gary Johnson at 6 percent and Jill Stein at 2 percent. In the HuffPost Pollster charts, Clinton leads by 7.5 points nationally in the 2-way race and by just under 7 points when third party candidates are included. There’s the beginning of a downturn for Trump detectable in the charts, but nothing conclusive yet. [Insights West, 2-way chart, 3-way chart]

A before/after test in Wisconsin shows Trump plummeting – Philip Bump: “When the Marquette University Law School polled Wisconsinites at the end of September, Hillary Clinton maintained a narrow lead over Donald Trump in the state…. The school went back into the field on Thursday to get a new sense of the electorate. As it turned out, this was an interesting moment to do so. On Friday afternoon, The Washington Post broke the story about Trump’s 2005 comments on ‘Access Hollywood,’ in which he is heard describing how being ‘a star’ allowed him to grope women. The pollsters noticed an immediate effect…. On Thursday, likely voters backed Trump by a one-percentage-point margin. This is well within the margin of error; since each day’s calls is only a part of the overall sample, the margins of error are necessarily larger. On Friday, the day the tape came out late in the afternoon, Clinton led by six points. On Saturday and Sunday, she led by 19. That’s a 20-point shift over the course of the survey, and why Clinton now leads Trump by seven points in a four-way contest. That drop-off post-tape held across demographic groups. (All of these shifts are in a four-way race.)” [WashPost]

Florida: Opinion Savvy’s October 10-11 poll reports Clinton leading Trump by 3 points, 47-44, Johnson at 5 percent and Stein at 1 percent. Overall, Clinton leads by just under 3 points in the HuffPost Pollster chart. [Opinion Savvy, Florida chart]

Maine: In a poll conducted by the Maine People’s Resource Center, mostly before the tape came out on Friday, Clinton leads by 8 points, 44 percent to 36 percent. Clinton already had a substantial lead in the state ― nearly 8 points on average in the HuffPost Pollster chart. [MPRC, Maine chart]

Missouri: A Monmouth University poll in Missouri shows the state mostly stable in the wake of the allegations, with Trump leading by 5 points, 46-41. That’s not much lower than the average 7-point lead Trump has in the HuffPost Pollster chart.  [Monmouth, Missouri chart]

Nevada: An internal poll conducted by PPP (D) for Nevada Senate candidate Catherine Cortez Masto,  puts Clinton up by 4 points over Trump, post-tape. HuffPost Pollster’s model gives her a narrower 1-point edge in the state. [PPP, Nevada chart]

Pennsylvania: A Bloomberg Politics poll conducted by Selzer & Co. gives Clinton a 9-point lead, 51 percent to 42 percent. HuffPost’s model gives her an average lead of just under 6 points. [Bloomberg, Pennsylvania chart]

EVEN ONE OF TRUMP’S FAVORITE POLLS SHOWS HIM FALLING BEHIND – Evan Halper: “Among Donald Trump’s favorite polls this election season is the USC/LA Times Daybreak tracking poll because it so often has shown him ahead when most other polls reported he was behind. But Trump is unlikely to cite the poll on Twitter or during any of his campaign events Wednesday. For the first time since early September, even the USC/LA Times poll has Hillary Clinton leading. The poll often is out of sync with other voter surveys because it uses different methodology. It asks voters to estimate, on a scale of 0 to 100, how likely they are to vote for a particular candidate and crunches the results for a daily forecast…The daily poll results often do not immediately reflect voter attitude shifts following a major event, like the release of a video last week in which Trump boasted of sexually assaulting women. That’s because the voters who participate are given a week to respond to each round of questions, and each day’s results reflect an average of the previous week’s responses. There generally is a nine-day lag before major opinion shifts emerge in the result.” [LAT]

How one 19-year-old man has helped to swing the panel toward Trump – Nate Cohn: “There is a 19-year-old black man in Illinois who has no idea of the role he is playing in this election. He is sure he is going to vote for Donald J. Trump….He’s a panelist on the U.S.C. Dornsife/Los Angeles Times Daybreak poll, which has emerged as the biggest polling outlier of the presidential campaign….Our Trump-supporting friend in Illinois is a surprisingly big part of the reason. In some polls, he’s weighted as much as 30 times more than the average respondent, and as much as 300 times more than the least-weighted respondent. Alone, he has been enough to put Mr. Trump in double digits of support among black voters. He can improve Mr. Trump’s margin by 1 point in the survey, even though he is one of around 3,000 panelists. …The U.S.C./LAT poll weights for many tiny categories: like 18-to-21-year-old men, which U.S.C./LAT estimates make up around 3.3 percent of the adult citizen population….The U.S.C./LAT poll does something else that’s really unusual: It weights the sample according to how people said they voted in the 2012 election…If the U.S.C./LAT poll were a normal poll, the 19-year-old from Illinois might have been in the poll only once. Most of the time, the heavily weighted young black voters would lean toward Mrs. Clinton — ensuring that the poll both had the appropriate number of black voters, and a relatively representative result. But the U.S.C./LAT poll had terrible luck: The single most overweighted person in the survey was unrepresentative of his demographic group.” [NYT]

The pollsters respond – Arie Kapteyn, director of the USC Dornsife Center for Economic and Social Research writes the listserv of the American Association for Public Opinion Research: “In this poll, we made the decision that we would not trim the weights to ensure that our overall sample would be representative of, for example, young people and African Americans. The result is that a few individuals from groups such as those who are less represented in polling samples and thus have higher weighting factors, can shift the subgroup graphs when they participate….Our confidence intervals (the grey zones) take into account the effect of weights. So if someone with a big weight participates the confidence interval tends to go up….Admittedly, the weight given to this one individual is very large, nevertheless excluding this individual would move the estimate of the popular vote by less than one percent. Admittedly a lot, but not something that fundamentally changes our forecast. And indeed a movement that falls well within the estimated confidence interval. So the bottom line is: one should not over-interpret movements if confidence bands are wide.”

HUFFPOLLSTER VIA EMAIL! – You can receive this daily update every weekday morning via email! Just click here, enter your email address, and click “sign up.” That’s all there is to it (and you can unsubscribe anytime).

THURSDAY’S ‘OUTLIERS’ – Links to the best of news at the intersection of polling, politics and political data:

-Nate Silver finds Donald Trump facing big trouble in post-debate polling. [538]

-Steven Shepard summarizes Trump’s polling “tailspin.” [Politico]

-Kyle Kondik sees mixed signals about Republicans’ strength in this year’s House races. [Sabato]

-David Wasserman, Reuben Fischer-Baum and Ritchie King chart the counties where Trump and Hillary Clinton have the most potential upside. [538]

-Sean McElwee, Jesse Rhodes and Brian Schaffner analyze the nation’s divides by race and class. [WashPost]

-Toni Monkovic talks with Decision Desk HQ’s Brandon Finnigan (R) about the race in Pennsylvania. [NYT]

-Few British voters regret their choice on Brexit. [Economist]

-Frank Luntz (R) has a replica Oval Office in his house for some reason. [Hollywood Reporter]