A new poll shows just how important turnout among certain groups of voters will be in determining whether Democrats take control of Congress after the midterm elections or if Republicans retain a majority.

By huge double-digit margins, African-Americans, Latinos, white women with college degrees, and young voters all prefer Democrats to win on Nov. 6, according to a new poll from NBC News and the Wall Street Journal.

Overall, 50 percent of the 645 likely voters surveyed for the poll preferred Democrats to win a majority, compared to just 41 percent who said Republicans.

Republicans did see an uptick in enthusiasm from September, though, the team of Democratic and Republican pollsters found.

Among registered voters, Republicans trimmed the Democratic advantage down to 7 points, 48 percent to 41 percent. That’s down from a 12-point lead for Democrats in that category from the September poll.

“The current data shows that the Democratic advantage has ebbed but still with a large advantage. And the GOP shows some life,” Democratic pollster Fred Yang said.

The study surveyed 900 registered voters between Oct. 14 and Oct. 17 via phone interviews. The margin of error for the full registered sample was plus or minus 3.3 percentage points. Among the 645 likely voters polled, the margin of error was plus or minus 3.9 points.

Key minority groups could fuel a Democratic victory next month, the numbers show.

Eighty-one percent of African-Americans prefer Democrats, compared to just 11 percent who prefer Republicans. Latinos want Democratic control of Congress, 66 percent to 26 percent. Democrats also have an edge among white, college-educated women — 61 percent to 28 percent — and people aged 18 through 34 — 58 percent to 32 percent.

Overall, women prefer Democrats by a 25-point margin, 57 percent to 32 percent.

Independents, a key voter bloc each cycle, prefer Democrats 41 percent to 27 percent.

Republicans lead among men, 52 percent to 38 percent, and white people, 49 percent to 41 percent. They also hold an 8-point advantage, 48 percent to 40 percent, among white women without college degrees.