Here's how the remaining toss-up races break down, state by state:
Though Indiana has typically been a reliably red state, the retirement of Republican Sen. Dan Coats has given an opening to Democrat Evan Bayh, a former governor and senator who retired in 2011. While the race is expected to be close, Bayh maintains a nearly 2.3 point lead in the polls, but that lead has been shrinking.
GOP Sen. Roy Blunt held a comfortable lead through the summer, but his race against Democrat Jason Kander, Missouri's secretary of state, has tightened considerably, with just a 1.5 point edge — less than the margin of error. The final count is expected to be close.
GOP Rep. Joe Heck is hoping to flip this Senate seat from blue to red, after the retirement of Senate Minority Leader Harry Reid. But Reid's handpicked replacement, Catherine Cortez Masto, has closed the gap, trailing by 1.4 percentage points. Heck has tried to distance himself from Trump, calling on him to quit the presidential race after the release of the "Access Hollywood" tape capturing his demeaning comments about women.
Clinton's lead in the Granite State against Trump may also help Democratic Gov. Maggie Hassan in her bid to unseat incumbent Republican Sen. Kelly Ayotte, who has struggled to distance herself from Trump after earlier citing him as a role model for children. Ayotte is holding onto a slim lead in the polls.
While the state was once considered a safe Republican seat, incumbent Sen. Richard Burr is in a tough fight against Democrat Deborah Ross, a former state legislator, who briefly led Burr in the polls earlier this month. Burr's campaign has also benefited from Clinton's aggressive campaigning in the Tar Heel State, where Burr leads by 1.5 percentage points.
Democrats are also hoping to flip a Republican seat in Pennsylvania, where incumbent GOP Sen. Pat Toomey is trailing Democratic challenger Katie McGinty, who has opened up a 3.8 point lead. Pennsylvania has a split congressional delegation but has voted for Democrats at the top of the ticket in the last six presidential elections.