There are a lot of caveats to that, including that the RCP average is just that, an average, and that this is head-to-head polling vs. the four-way. But the broader point worth remembering is that the general election race was already a huge mountain for Trump to climb, even before the Friday release of the 2005 tape in which he makes lewd comments about women.
Three polls released this weekend make that point as well. Live-caller polling generally takes a few days, so the new surveys were completed before the revelations on Friday. The polls are from Iowa (conducted by the Des Moines Register), as well as Florida and Pennsylvania (conducted by NBC, the Wall Street Journal and Marist). Trump leads in Iowa by four points, about where he had been in the polling average. Clinton leads by three in Florida and 12 in Pennsylvania, also in line with the existing averages.
Since the first presidential debate, though, polls in each state had shifted to Clinton. At the time of the debate, Trump had pulled close in Pennsylvania; Clinton now has a wide lead. Trump's lead in Iowa has dipped. The tie in Florida is now a Clinton advantage.
Remember: Trump has essentially no path to victory without winning Florida. If he sweeps the other nine states out of the 10 closest, save Florida, Clinton still wins by 38 electoral votes. That includes Trump victories in Nevada, North Carolina, New Hampshire and Wisconsin, and gives him his leads in Ohio and Iowa.
There are details in that Iowa poll worth pointing out. Much of Trump's support continues to stem heavily from opposition to his opponent, as we've seen elsewhere, though the difference between Trump and Clinton on that measure is smaller in Iowa.
Trump's support, though, is much stronger among less-frequent or new voters. Here's the Des Moines Register:
Trump is also finding success among new and marginal voters in Iowa’s electorate. The candidates are virtually tied among voters who have cast ballots in most general elections — Trump leads 42 percent to 41 percent. But he has a much wider lead, 47 to 33, among those who are either voting for the first time or have voted irregularly in the past.
That was similar to what we saw in the last survey from the same pollster before the Iowa caucus. At that point, the Register reported that "[a]mong first-time caucusgoers, Trump has a 16-point lead. But the universe of experienced caucusgoers is bigger, where [Ted] Cruz has a 3-point lead." What happened next? Cruz out-organized Trump in the state and, despite trailing in that poll by five points, pulled out a three-point victory.
Trump's campaign has an admittedly weak voter turnout effort. He's bolstered by the Republican Party, which has revamped its turnout operation this cycle. On Saturday, Politico reported that the party might be rethinking its investment in their candidate, shifting resources from Trump to down-ballot races. If that were to happen, Trump's turnout effort in Iowa would become nearly nonexistent. FiveThirtyEight reports that Hillary Clinton has 23 more field offices in Iowa than Trump. (A party spokesman says the reports of cutting resources are not true.)
Every single number that precedes this sentence comes from information gathered prior to the new Trump revelations. It's possible that his core base of support doesn't move an inch after the video's release; we've certainly seen this happen enough times. But Trump's core base of support has also proven to be too small to give him a lead that would win him the White House. After that first debate, the race moved further out of Trump's reach. Even if it doesn't move at all after the tape, he has less than a month to turn things around and no clear plan to do so.
If voters do turn on Trump thanks to the tape? If the wavering Republican and independent women who have accounted for much of Trump's problem in catching up to Clinton give up on him once and for all? Well, that list of the 10 closest states might just keep getting more interesting.
Update: A new poll from ABC News and SRSS suggests that the tape has had an effect. The sample size is small, but more than half of respondents said the tape made them less likely to vote for Trump. "There was a stark gender gap," ABC's Rachel Tillman writes, "with 62 percent of women less likely to vote for him while 55 percent of men say it will make no difference on their vote." More than 4-in-10 respondents say that they think Trump should drop out of the race.