Bill Shuster inherited PA's 9th congressional district from his father in 2002. In most election cycles, he runs unopposed as the district is mostly Republican.
This primary season he won the Republican nomination over Art Halvorson by only 1009 votes. Halvorson, however, also received 1069 write-in votes for the Democratic ticket. Now, Halvorson has accepted the Democratic nomination against Shuster despite the fact that Art is more conservative and running as such.
Their names are the only ones on the ballot for that congressional district.
I want to know if there is precedent for this kind of race and whether it has ever worked.