Scoop: Democrat Senate Super PAC targets 4 Republican seats

The Democrats' main Senate super PAC is booking another $54 million in TV ads for the midterm campaign's final stretch, targeting four Republican-held seats.Why it matters: The new reservations offer a roadmap to where Democrats think they can flip seats.Republicans' last major advertising reservation was aimed largely at defending incumbents — and protecting the GOP "red wall" to preserve their majority.By the numbers: Senate Majority PAC, the super PAC aligned with Senate Minority Leader Chuck Schumer, is expanding its footprint in four battlegrounds.Ohio: $24 million more behind former Sen. Sherrod Brown, bringing its total reservation to $60 million.Iowa: $17 million more for state Sen. Josh Turek, increasing the total to $30.5 million.North Carolina: $11 million more for former Gov. Roy Cooper, increasing the reservation to $42.5 million.Alaska: $2 million more behind former Rep. Mary Peltola, bringing the cycle total to $11 million.What they're saying: "Injecting new resources into the four most competitive Senate races shows just how clearly the battleground map has shifted toward Democrats," Senate Majority PAC spokesperson Lauren French said.Zoom out: Senate Leadership Fund, the super PAC aligned with Republicans and Majority Leader John Thune, remains significantly better capitalized.As of the end of June, Senate Leadership Fund reported $238 million in cash on hand, compared with $126 million for Senate Majority PAC.What's next: Wednesday's announcement won't be SMP's last. The group expects to make additional TV reservations before Election Day and isn't disclosing its digital spending plans.In April, SLF announced plans to spend $342 million for the cycle across all platforms, including get-out-the-vote operations.