The first national polls taken in the immediate aftermath of the election’s latest October surprise suggest it’s having a limited impact on the presidential race so far. But there are a few swing states where the bombshell letter FBI Director James Comey sent to Congress on Friday could still have a disproportionate effect.

Already, the persistent and overriding unpopularity of Hillary Clinton and Donald Trump had created more volatility than usual for the final week of a presidential campaign — as evidenced by the larger percentages of undecided voters and those backing third-party candidates.


And with Clinton’s email scandal vaulted back into the news by Comey’s ambiguous letter to Congress last week, that instability creates more uncertainty than usual going into the last full week of campaigning across the potentially decisive states in the Electoral College — uncertainty that isn’t uniform across the map.

In the most-contested battleground states, voters have been bombarded with seemingly nonstop television advertisements and ground-game mobilization efforts. In general, polls in these states show fewer undecided voters — though the percentage of voters backing third-party candidates is more variable.

Polls in some battleground states, like Colorado and New Hampshire, show large percentages of voters who aren’t committing to Clinton or Trump. But in states like North Carolina and Florida, while the percentage of undecided voters remains historically high in some polls, there are fewer third-party voters, creating less opportunity for Trump or Clinton in the closing days.

EIther way, at this stage in the campaign those are significant pools of voters who have not committed to either major-party nominee. A late-breaking bombshell like Comey’s letter threatens not just to prod voters still on the fence — it could also energize Republicans and depress Democrats at just the right moment to boost Trump and dog Clinton.

There are limits, however, to how widespread that effect might be because of early voting in some battleground states — which not only makes it easier for lower-propensity voters to participate, but also has allowed Clinton’s campaign, which is better organized in most swing states, to bank votes over the past few weeks. That’s especially true in Florida, where 3.6 million people had voted as of the latest data available Sunday; North Carolina, where 1.1 million residents had voted as of Friday morning; and Nevada, where more than 430,000 ballots had been cast as of Sunday night.

Colorado’s nine electoral votes have appeared out of reach for Trump for most of the campaign, but Libertarian Gary Johnson and Green Party nominee Jill Stein have generally run stronger there than in other states. The most recent live-telephone survey in the state is two weeks old, but the Quinnipiac University poll in mid-October showed Johnson at 10 percent and Stein at 3 percent. Additionally, a combined 6 percent of likely voters in that survey said they were undecided or preferred another candidate — slightly more than simultaneous surveys in other battleground states.

Trump is advertising in Colorado, but Clinton’s campaign and a super PAC supporting her have been off the air in the state, which Democrats thought was safely in Clinton’s column. Moreover, the state’s all-mail voting could help alleviate any decrease in Democratic enthusiasm over the email issue.

Like Colorado, Virginia is another state Trump is still contesting in which Democrats have felt comfortable enough to pull their television ads. There is still a large percentage of voters potentially up for grabs there, however: While two polls last week gave Clinton large leads, undecideds and third-party supporters combined for 12 percent of the electorate in a Quinnipiac University poll and 15 percent in a Christopher Newport University poll . Johnson, Stein and Evan McMullin — the former House GOP staffer running as an independent in fewer than a dozen states — are all on the ballot there.

Johnson and Stein are also running strong in New Hampshire, where Clinton has led consistently in the polls, according to two live-caller polls conducted last week. Both polls, from Monmouth University and NBC News/Wall Street Journal/Marist , showed 5 percent of likely voters undecided or preferring another candidate. But the NBC News/Wall Street Journal/Marist poll shows Johnson at 10 percent and Stein at 4 percent — which are both larger percentages than any third-party candidate has received in the state since 1996. The Monmouth University poll showed smaller vote shares for Johnson (7 percent) and Stein (1 percent).

To the extent the uncommitted voters are Republican leaners who have been hesitant about Trump, the resurrection of the FBI investigation into Clinton’s use of a private email server could help them come home to the GOP nominee.

But University of New Hampshire professor Dante Scala pointed out that in a University of New Hampshire poll earlier this month, just as many purely undecided voters identified as moderates and independents.

“I would not think this news is enough to push them [to one candidate] for good,” Scala said in an email Sunday, adding that the future of these moderate voters “depends on next week.” (New Hampshire doesn't allow early voting.)

In other hotly contested battleground states, late developments appear less likely to move the needle — in part because fewer voters are on the fence, but also because more votes have already been cast.

The 3.6 million votes that had been cast in Florida as of Friday morning represents more than 40 percent of the state’s 2012 total vote. And fewer voters are supporting third-party candidates in the largest battleground state: A Siena College poll conducted last week for the New York Times’ “Upshot,” in which Trump led Clinton by 4 points, showed Johnson at 4 percent and Stein at 2 percent, with 6 percent undecided or backing another candidate. Clinton and Trump were deadlocked in an NBC News/Wall Street Journal/Marist poll, also released Sunday, with 7 percent saying the supported neither or another candidate, and only 1 percent undecided.

In North Carolina, the 1.1 million votes already cast is about a quarter of the total 2012 vote. Clinton had a 6-point lead in an NBC News/Wall Street Journal/Marist poll out on Sunday, with 5 percent supporting neither or another candidate and 2 percent undecided.

And in difficult-to-poll Nevada, the early vote accounted for more than 40 percent of the total 2012 vote. Still, the state has a history of backing third-party candidates, and disgusted voters can also choose the “none of these candidates” option on the ballot.

The electorate is also more hard-wired in other states with limited early-voting opportunities, like Pennsylvania, which is a must-win state for Trump, especially if he loses North Carolina. Still, there are some opportunities for Trump to gain: There is no early voting in Pennsylvania, so the bulk of the votes will be cast after the Comey letter. And another Siena poll conducted for "Upshot" last week showed Clinton leading by 7 points, but only at 46 percent. Johnson was at 6 percent and Stein at 3 percent, and 6 percent were undecided or preferred another candidate.

If the email issue does create opportunities for Trump, those might come in states where the campaigns have been less active thus far. The Republican nominee, perhaps uncoincidentally, was in New Mexico on Sunday night and is traveling to Michigan on Monday and Wisconsin on Tuesday.

Polling has been sparse in New Mexico, but polls of Michigan and Wisconsin have suggested there are more uncommitted voters there than in other states. An EPIC-MRA poll in Michigan, which Republicans last won in 1988, showed the undecided share at an unusually high 15 percent. Michigan, like New Hampshire and Pennsylvania, doesn't allow in-person early voting.

There are fewer undecided voters in Wisconsin, which hasn’t gone for the GOP presidential nominee since 1984: A Monmouth University poll two weeks ago showed Johnson at 6 percent and Stein at 1 percent, and a combined 7 percent undecided or preferring another candidate.