Morning Digest: Senate GOP has a big ad spending edge, but Democrats get more 'bang for their buck'

Perhaps no race better demonstrates this in action than the Arizona Senate race. The GOP firm OH Predictive Insights relays that during the week of Sept. 19, Democratic Sen. Mark Kelly and his allies outspent Republican Blake Masters' side 52-48 in advertising. Anyone just looking at raw dollar amounts would conclude that the two parties aired about the same number of ads during this period, but that's not the case at all. In reality, Kelly's side had a 4-1 advantage in ​​gross ratings points, which measure how many times, on average, members of an ad's target audience have seen it.

Republicans can blame Masters, whom NBC says has spent all of $9,000 on ads during most of September, for much of the imbalance. The Senate Leadership Fund last week canceled all its planned ad time in Arizona while arguing that other super PACs would step in, and this data shows why Masters badly needs this prediction to finally come true.

Outside groups, though, can still air more ads than well-funded candidates if they're willing and able to spend massive amounts the way the GOP is in Ohio. Cleveland.com's Andrew Tobias reports that Republicans are airing 20% more commercials than their Democratic foes in the Buckeye State after spending or reserving almost three times as much. Democrat Tim Ryan, writes Tobias, is responsible for 83% of the ads coming from his side compared to just 8% for Vance, but the Senate Leadership Fund has committed $28 million here to bail out its underwhelming nominee.