Just hours ahead of the first 2016 presidential debate, Hillary Clinton continues to lead Donald Trump by 5 points, 45 percent to 40 percent, unchanged from last week, according to the latest NBC News|SurveyMonkey Weekly Election Tracking Poll.
Libertarian candidate Gary Johnson trails behind with 10 percent support, and Green Party candidate Jill Stein has 3 percent support.
In a two-way match-up without the third-party candidates, Clinton has a 7-point advantage over Trump, 51 percent to 44 percent. The margin is up from 5 points last week among likely voters.
These results are according to the latest NBC News|SurveyMonkey Weekly Election Tracking poll conducted online from September 19 through September 25.
The debate Monday night at Hofstra University is the first time Clinton and Trump will be head-to-head on stage together, and the campaigns have stressed the importance of key groups like millennial voters.
More from NBC News:
Poll: LGBT voters support Clinton over Trump
Early get-out-the-vote efforts favor Clinton: Ballot requests in battleground states
Hillary Clinton regains momentum against Donald Trump: Poll
Younger voters tend to support Democratic candidates, and they were an important group to President Obama's victories in 2008 and 2012. Clinton had some trouble securing the support of millennials throughout the Democratic primaries. Third-party candidates Johnson and Stein have done well with young voters and many Democrats fear that millennials might support third-party candidates or not vote at all.
In the four-way general election match-up, 49 percent of those under age 30 support Clinton, and 26 percent support Trump; 16 percent of 18-29 year old likely voters support Johnson, and 7 percent support Stein. Millennial voters support the third-party candidates more than older voters—only 5 percent of those 65 and over support Johnson and only 1 percent support Stein.
Trump's support among young voters remains consistent from last week. Likely voters under 30, however, have shifted support from Johnson to Clinton. Last week, 18 percent of likely voters under 30 supported Johnson. This week, 16 percent said they support him.
Clinton, on the other hand, went from 47 percent support among likely voters 18-29 years old to 49 percent support. Support among that group for Stein went from 8 percent last week to 7 percent this week.
This week's data, which shows that third-party candidates Johnson and Stein do better among younger voters than other generations of voters, means that Clinton may need to both secure the support of millennials as well as motivate them to turn out on Election Day.
The NBC News|SurveyMonkey Weekly Election Tracking poll was conducted online September 19 through September 25, 2016 among a national sample of 13,598 adults who are likely to vote. Respondents for this non-probability survey were selected from the nearly three million people who take surveys on the SurveyMonkey platform each day. Results have an error estimate of plus or minus 1.1 percentage points. For full results and methodology, click here.