http://www.congressionalleadershipfund.org/race/pennsylvania-district-18/
Problem is: they paid for a mailing which convinced pro-gun Democrats to vote for a Democrat, at a time that they (at least enough to tip the election) would have either likely not voted for what typically would be an anti-gun Dem, or would have crossed over and voted R instead.
It was an interesting attempt at scaring anti-gun Democrats away from Lamb.
Instead, it encouraged pro-gun Democrats to vote _for_ Lamb.
Massive fail.
http://www.congressionalleadershipfund.org/
If the ad is really funded by the Congresional Leadership Fund, it's a Republican CAP.
https://en.wikipedia.org/wiki/Congressional_Leadership_Fund
Republican super PAC warns Democratic voters that their candidate supports gun rights