Nationally, Democrats have 53.1 percent of all votes counted while Republicans took 45.2 percent.
Not since the Watergate scandal have Democrats run up such a large margin of victory in midterm House races, NBC News data showed.
With votes continuing to be tallied more than two weeks after Election Day, Democrats hold a lead over Republicans in the House popular vote by more than 8.6 million votes.
That's the largest total victory in a midterm House election since Democrats defeated Republicans by more than 8.7 million votes in 1974, just months after President Richard Nixon resigned from office in disgrace.
And the number is continuing to inch up.
As of noon on Wednesday, Democratic House candidates won 58,990,609 votes while their Republican counterparts pulled in 50,304,975. That means that, so far, Democrats won 53.1% of all votes counted while Republicans earned 45.2%.
Democrats currently hold a 234 to 199 edge over Republicans in the incoming House, which will start in January, according to NBC News. NBC News has yet to call two races — Georgia's 7th Congressional District and Utah's 4th Congressional District.
So far, Democrats have a net gain of nearly 40 House seats.