'No suburban district is safe': GOP strategist hits the panic button over PA-18
Marine veteran and former federal prosecutor Conor Lamb speaking at Democrats' nominating convention. Photo via the Pennsylvania Democratic Party.

Democrat Conor Lamb's apparent victory in Pennsylvania's special congressional election on Tuesday is sending waves of panic through the Republican Party, as it came in a seemingly safe district that had voted for President Donald Trump by 20 points in 2016.

A Republican strategist who talked with Business Insider says that the GOP should not try to put any rosy spin on the results of the election, as he said they would have been disastrous for the party even if Republican candidate Rick Saccone had pulled out a razor-thin victory.

"The narrow margin in a district the president won handily should be a serious wake-up call for Republican incumbents across the map," the strategist said. "No suburban district is safe and every candidate better be ready for the most difficult cycle of their career."

Another GOP strategist similarly told Business Insider that the loss should "serve as a wake-up call to everybody" in the GOP.

Lamb's district not only voted for Trump by 20 points in 2016, it is also classified by analysts as a Republican +11 district, meaning a generic Republican has an inherent 11-point advantage over a generic Democrat in any election. For perspective, there are more than 100 Republican-held seats whose districts are more Democratic-friendly than PA-18, including those of Rep. Paul Ryan (R-WI), whose district is rated as Republican +4, and Rep. Devin Nunes (R-CA), whose district is rating as Republican +8.

Democrats need to flip 24 seats to win a majority in the House of Representatives in November's midterm elections.