Republicans gain ground in Senate races in Pennsylvania and Wisconsin

After a grueling summer, Republicans are finally making headway in protecting their top two firewalls in the race for the Senate.

Holding onto at least one of the GOP-held seats in Wisconsin and Pennsylvania — ideally both — is critical if the party wants to flip the Senate. But Wisconsin Republican Sen. Ron Johnson and Pennsylvania Republican Senate nominee Mehmet Oz began the general election with poor favorability ratings and a spending disadvantage on TV.

By contrast, the Democratic candidates, Wisconsin Lt. Gov. Mandela Barnes and Pennsylvania Lt. Gov. John Fetterman, had...