“The accusations against Sinema are part of a larger line of attack that Martha McSally and Republicans are making against Sinema, which is simply that she is not credible,” says the UVA Center for Politics’s Kyle Kondik. “For instance, a major theme of the advertising being used against Sinema has been to argue that she is more left-wing than she lets on. The message, basically, is that Sinema is not the moderate that she has presented herself as — again, from the GOP perspective.”