An email leaked from the North Carolina GOP shows Republicans in the state are worried about their prospects for 2018 after the surprise results of the Pennsylvania special election this week. 

In an email obtained by the Raleigh News & Observer, North Carolina GOP House Caucus political director Matt Bales warned congressional Republicans in vulnerable seats of a possible wave of Democratic support that could potentially cost the GOP its majority in the state House and Senate come the 2018 midterm elections.

Pennsylvania Democrat Conor Lamb looks poised to win what was thought to be a safe Republican district, where President Trump won by nearly 20 points in 2016. 

“The outcome is yet another example of the Democratic base being fired up and the Republicans not turning out their voters,” Bales said in the email. “The momentum on the Democratic side is real.”

The email singled out 23 incumbent Republicans districts where Trump also won by similar margins, but that could face what many Democrats hope to be a referendum against the president. 

North Carolina Democratic Party spokesman Robert Howard wrote that the email “shows just how terrified Republicans are of the upcoming election,” according to the News & Observer. 

The Pennsylvania district fell despite a visit by Trump himself and Vice President Pence, as well as more than $10 million in extra funding by GOP affiliated groups. House Speaker Paul Ryan (R-Wis.) tried to assure Republicans this week that the special election was not the norm and that the national party’s majorities would be safe going into this year’s midterm elections.