The head of communications for the Delaware Republican Party announced Friday morning that he is leaving the state.

The announcement by Tom Doheny comes 11 days after conservative pundit Christine O’Donnell shocked the nation by upsetting Rep. Mike Castle in the First State’s Senate Republican primary. Castle was the favorite of state and national party leaders and viewed as the only Republican nominee who could win in November.

“After a hard-fought campaign, I have decided to move on to a new opportunity working for the Republican Party of Pennsylvania,” Doheny wrote in a message to supporters. “It has been both an honor and a privilege to serve Congressman Castle, Chairman Tom Ross, and all of our Republican candidates during this election season.”

Like Ross, the state party chairman, Doheny was outspoken in his criticism of O’Donnell in the days before the primary.

“This is a candidate who not only spins different elements of different stories, but also flat-out lies,” Doheny said of O’Donnell in an interview with Roll Call a week before the primary.

In a subsequent interview with Roll Call on Friday morning, Doheny said he was leaving for the good of the party.

“I worked very hard to promote and get Castle elected. And things didn’t go the way we had planned,” he said. “I think the party will be better served with someone else who can start with a clean slate.”

Doheny will manage press for 19 Congressional candidates in Pennsylvania as director of Congressional communications for the state party.