A wide range of evidence indicates that Democratic voters are poised to vote in numbers unseen in a midterm election in at least a decade.

Democrats have largely erased the turnout deficit that hobbled them during the Obama presidency, according to results from more than 50 New York Times Upshot/Siena College polls of the most competitive House battleground districts.

Democrats may even be poised to post higher turnout than Republicans, a rarity, in many relatively white suburban districts on Nov. 6.

But it’s not clear if this blue turnout surge will extend much further, particularly among young and nonwhite voters. Whether Democrats turn out broadly could make the difference between a fairly close fight for control of the House and sweeping Democratic gains of 40 or more seats.