Political advertising in this year's midterm elections is breaking previous records, and almost half of that money is going to local TV stations. The surge comes even as advertisers have moved more marketing dollars to social platforms, streaming channels and other digital media.

Politicians and PACs are still spending billions on local stations despite concerns that TV ads are costlier to produce and less efficient at targeting prospective voters. This election will show how much that approach still holds in a transformed media environment.

Danielle Butterfield, a Democratic strategist and executive director of Priorities USA, said both parties are spending a disproportionate share of their budgets on broadcast TV. She pointed to a "muscle memory" of needing to chase and match what the other side is doing.

Political consultants and television executives argue that broadcast TV can still reach a larger swath of the population more quickly than other media. They also point to devoted audiences for nightly news, sitcoms, dramas and football games.

Gregg Siegel, senior vice president of national sales at Sinclair Broadcast Group, said local anchors and reporters are trusted, familiar voices. They live in the communities they cover, raise families there and are part of the fabric of those communities, he said, creating a level of credibility that is difficult to replicate on other platforms.

The amount of money being spent on political advertising this election cycle is staggering, helping to boost the bottom lines of major local broadcasting companies such as Sinclair, Nexstar Media Group, Gray Media, Tegna and the E.W. Scripps Company. The trend is especially evident in Texas.

Sources: The New York Times Business.