Analysis: How did the Democrats come close to achieving their largest majority in the House of Representatives in 35 years?

Analysis by CNN's Aaron Blake

(CNN) - It is estimated that Democrats may achieve their largest majority in the US House of Representatives since the early 1990s, as their number of seats may exceed 260, according to a review conducted by CNN of the election results that have not yet been announced.

So far, CNN expects Democrats to win 245 seats, a net increase of 34 seats, while Republicans trail them by nearly 100 seats, with 147 seats.

Democrats are also currently leading in many of the remaining 43 election races.

They enjoy comfortable leads in Arizona's 1st and 6th Districts, with more than 80% of the votes counted.

They also lead in about a dozen other races by a margin of between one and five percentage points, but due to a sufficient number of votes that have not yet been counted, the results for these districts have not been decided. This includes about four districts in North Carolina, in each of which Democrats lead by two percentage points.

Moreover, Democrats lead by less than one percentage point in five congressional districts: Colorado's 4th District, Florida's 9th District, Minnesota's 1st District, North Carolina's 5th District, and Tennessee's 4th District.

In total, the Democrats are ahead in 264 districts. If they win them all, they will obtain a majority of 264 seats, compared to 171 seats for the Republicans. This will be their largest majority since the period between 1991 and 1993, when Democrats held 267 seats.

It is noteworthy that the Democrats reached 257 seats during the electoral “wave” in 2008, which brought Barack Obama to the White House.

The total number of seats that one party took from the other is likely to be less than what happened in the 2010 elections, when Republicans took more than 60 seats.

But one of the main reasons that enabled the Republicans to grab such a large number of seats at that time was that they started the elections with a relatively small number of seats, thanks to the large majority achieved by the Democrats after the 2008 elections, in addition to the presence of a large number of Republican-leaning districts that they were able to win.

By contrast, the House of Representatives in the 2026 elections was very narrowly divided between the two parties. However, Democrats were able to achieve significant gains that, according to current indicators, appear historic.