BBC reporter Anthony Zucker: The Democratic Party’s historic victory has deeply penetrated the Republican vote base and captured the territory.

This is destined to be a historic night for the American Democratic Party. The party has not only won control of the U.S. House of Representatives, but is also moving toward flipping the Senate.

Democrats first scored a stunning victory in the Senate. Anne Andrews defeated Darlene Graham, who was appointed to the seat following the death of her brother, Senator Lindsey Graham.

Even a few months ago, few analysts thought the seat was on the line.

Two Senate races that were considered close a year ago are now easy wins for Democrats, including the re-election of Jon Ossoff in Georgia and an open Republican-held seat in North Carolina.

Former Democratic Gov. Roy Cooper defeated Republican insider Michael Wortley in the North Carolina race. It's the first of four seats Democrats need to take back control of the Senate. With South Carolina in hand, they're already halfway there.

Now, outside attention has turned to the counting results of Republican-controlled Senate seats in Texas, Kansas and Ohio.

CBS, the BBC's partner in the United States, believes that the Senate races in Texas and Kansas are leaning toward the Democratic Party. As for the Texas gubernatorial election, the current Republican Governor Greg Abbott was considered a sure winner a year ago, but now he is seen as uncertain.

Meanwhile, Democrats won a majority in the House of Representatives for the first time since 2022.

A look at a few key election battles shows why.

In Florida, the Republican-controlled state Legislature redrawn the boundaries of three Democratic-held districts to make it easier for Republicans to win.

However, they lost all three seats.

Other House races in the state that were thought to be easily winnable by Republicans are now mired in fierce battles.

For example, Democrats captured open seats in western North Carolina and Kentucky and appear to have a strong chance of expanding their gains in Virginia and Indiana.

Their victory was driven by strong turnout among Democratic supporters, especially black voters in southern states, while also winning back Latino voters in Florida. Just two years ago, these voters supported Republicans.

In counties in South Carolina with predominantly black residents, Democratic senatorial candidate Andrews' vote performance was significantly better than Harris Harris's performance in the 2024 presidential election.

In Miami-Dade County, where Trump won that year, the Democratic candidate is back in the lead.

If there's a silver lining for conservatives, it's that Florida overall still appears to be leaning to the right.

Republican Senator Ashley Moody was re-elected with a slight margin, and Representative Byron Donalds also successfully ran for governor. But the Sunshine State may be one of the few bright spots for the Republican Party.

While voter sentiment appears to have shifted across the board against President Donald Trump and the Republican Party, the United States is a vast country with unique geographic and demographic characteristics.

The Democratic Party's good electoral performance in the east does not necessarily mean that it will perform the same across the country. However, preliminary results in the central U.S. appear to be following trends along the East Coast.