Riding a surge of enthusiasm in opposition to President Trump, more Democrats turned out in the primaries for House elections than Republicans this year — the first time that has happened since 2008.

Why it matters: 2008 was the last time Democrats won a majority in the House. They lost it in 2010, when Republican primary turnout skyrocketed and Democratic turnout plummeted — the reverse of what's happening now.

What's next: David Brady, electoral politics expert and senior fellow at the Hoover Institution, predicts around a 7% Democratic turnout advantage in November driven by women, and particularly Independent women.