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.

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.