The Democratic primaries helped: Yes, the competitive, down-to-the-wire, clash-of-the-titans battle between five-term-incumbent party-switcher Arlen Specter and Joe Sestak drove Democratic interest and turnout, and Burns had nothing comparable on the Republican side. But does that factor account for a 12,000-vote margin?

Actually, it might. Note that in this district, voters cast their ballots for the primary for November’s election and the special election for the remainder of Murtha’s term on the same day. In the primary, 83,000 Pennsylvanians cast ballots on the Democratic side; only 46,000 did on the GOP side. In the special election, it was about 71,000 votes for Democrat Critz, 59,000 for Burns. In other words, at least 13,000 of Burns’s voters were not interested in casting a ballot in the GOP primary, which suggests that most were either Democrats or independents.

So where were this district’s Republicans? In 2008, Bill Russell had 113,000 votes against Murtha, in what was, obviously, one of the most dramatic Election Days in recent memory. Both John McCain and George W. Bush had 133,000 votes. Yes, it’s a special election, and turnout is always significantly lower for elections not held in November. But a key part of winning a special election is getting out the vote among your party’s base, and in this area, the Burns campaign dramatically underperformed. Traditionally, Republicans perform better than usual in special elections.