Rod BlumPhotographer: Scott Olson/Getty Images
A Bloomberg analysis of post-Labor Day TV advertising, announced media buys by the largest super political action committees, Federal Election Commission filings and interviews with strategists shows that more than half a dozen House contests rated as competitive have largely fallen off the map when it comes to the allocation of major national GOP resources.

That could hurt election prospects for Republican incumbents Rod Blum of Iowa, Keith Rothfus of Pennsylvania and Mike Coffman of Colorado, while boosting the chances of Democrats like Mikie Sherrill in New Jersey and Dan McCready in North Carolina…

All of the districts where national Republicans appear to be either holding their powder or in retreat are currently held by the GOP. If those districts are lost, they would offer a significant down payment on the 23 seats Democrats need to take control of the House and essentially halt President Donald Trump’s agenda in Congress.