Anthony Zurcher: Democrats surge into Republican territory as party eyes historic night

This is already shaping up to be historic night for Democrats, with the party on course to win control of US House of Representatives and on their way to flipping the Senate, too.

The Democrats notched their first shock win in the US Senate, when Annie Andrews beat Darline Graham, who had been appointed to the seat after the death of her brother, Senator Lindsey Graham.

Few analysts had that seat in play even a few months ago.

Two Senate races that a year ago were thought to be battlegrounds have turned out to be slam dunks for the Democrats - Jon Ossoff's re-election in Georgia and the open Republican-held seat in North Carolina.

That North Carolina contest, where former Democratic Governor Roy Cooper bested Republican Party insider Michael Whatley, was the first of the four pick-ups Democrats need in order to wrest control of the Senate. With South Carolina in the bag, they are halfway home.

Attention has now turned to vote counts in Republican-held Senate seats in Texas, Kansas and Ohio.

The BBC's US partner CBS News is rating the Texas and Kansas Senate races as leaning Democrat. The governor's race in Texas, where just last year incumbent Republican Greg Abbott was a prohibitive favourite, is now considered a toss-up.

Meanwhile, the Democrats are poised for the kind of victories that will help secure a House majority for the first time since 2022.

A look at the key races offers plenty of reasons why.

In Florida, Republicans in the state legislature had redrawn the boundaries of three Democratic-held seats to make it much easier to for them to win.

They lost all three.

Other House races in the state, where Republicans expected to win by comfortable margins, have turned out to be dogfights.

Democrats flipped open seats in western North Carolina and Kentucky, for instance, and appear well placed to make gains in Virginia and Indiana.

They're doing it on the back of high Democratic turnout, particularly by black voters in the south, and winning back Hispanic voters in Florida who had supported the Republicans just two years ago.