Democrats take down six Republicans, close in on House control

Democrats are surging toward control of the U.S. House after defeating six Republicans in key battleground races, according to The Associated Press. The wins landed in the districts both parties had circled as decisive, and they leave Democrats within reach of the majority.

The AP doesn't guess at outcomes. Its Decision Team declares a winner only when it is certain the trailing candidates no longer have a path to victory. Vote counts are gathered from local election officials in thousands of races nationwide and reported as soon as they are available.

Tabulating American elections is old muscle for the wire service — AP first counted U.S. vote totals back in 1848. At the reporting-unit level, the shift in vote margin reflects two-party vote share, a measure of how a given precinct or county moved.

Behind the running totals sits a large crew: designers, developers, researchers, photo editors, reporters and project managers who build and check the results operation. Editing and project management teams oversee the final numbers before they publish.

The fight for the House isn't over, and the picture will sharpen as remaining votes are counted and reported. For now, the six flipped seats have Democrats marching in one direction.