Nearly half of college students say they'll "definitely" vote this year, according to a survey by College Reaction, a group that measures public opinion among college students.

Why it matters: If true, that kind of turnout could help Democrats, since Republican students are more lukewarm about whether they'll vote. But in reality, young voters aren't exactly known for rushing to the polls in midterm elections. It would take a sharp break with recent history for that to become a reality.

By the numbers:

Only 18% of college students voted in the 2014 midterm elections, according to the group.

voted in the 2014 midterm elections, according to the group. By contrast, about 48% of college students voted in 2016 and 45% did so in 2012, according to a study by Tufts University.

about 48% of college students voted in 2016 and 45% did so in 2012, according to a study by Tufts University. If the enthusiasm in the new survey is real, it's a change from earlier surveys this year. One, released in July by the Public Religion Research Institute, found that just 28% of young adults said they were sure to vote in 2018, compared to 74% of seniors.

Go deeper:

Turnout surges among young voters in battleground states' primaries

Wave watch: Inside the Democratic primary turnout surge