The WG’s David Winston explains similarities between the PA-18 special election and a similar defeat for Republicans in 2010:
“In 2010, the special election in Pennsylvania’s 12th District was a tough loss when history dictated Republicans should’ve expected to pick up seats in congressional elections in a nonpresidential year. In reality, that defeat ended up being a gift to the GOP. The unexpected loss jolted Republicans out of their complacency.”