The aim of the strategy, detailed in nearly two dozen interviews with party officials and strategists, is a tacit acknowledgement of the ominous political environment Democrats are up against this year. The goal is to stop Republicans from padding their 17-seat edge and keep the party within striking distance of the majority in 2016, a presidential election year that could well be more favorable to Democrats.

On Friday, House Majority PAC, a leading Democratic super PAC and one of the biggest players in congressional races, will begin placing its first round of TV ad reservations, according to an outline first shared with POLITICO. Of the 24 districts the group is reserving commercial time in, 18 of them are occupied by party incumbents. The ads will begin running around Labor Day, when the midterm sprint begins in earnest…

Operatives working with Democratic groups say they’ve been tasked with examining how much damage incumbents have incurred from a wave of attacks funded by Americans for Prosperity, a Koch brothers-funded outfit. They’ve been conducting polling much earlier in the election year than they initially anticipated.

Democrats privy to the survey data say West Virginia Rep. Nick Rahall, a 19-term incumbent who’s been pummeled by the Koch ads, now trails his Republican opponent significantly. Two other Koch targets, Arizona Reps. Ann Kirkpatrick and Ron Barber, have seen their poll numbers drop but are in better shape than Rahall.