When your religion clearly states that anyone who doesn't believe in Jesus is going to suffer through the great tribulation, then the term Blood Libel cannot mean anything other than it has for 2000 years. This isn't a dog whistle. It's a siren that can be heard around the world.
Representative Giffords is Jewish. Her aide, Mr. Zimmerman, was Jewish. Using the term Blood Libel is not a mistake here. It is an obvious call out to Sarah Palin's rapture-ready fans who anxiously await the return of Jesus, when anyone who doesn't accept Jesus as their savior (Jews) will be subjected to the great tribulation, a period of "...worldwide hardships, disasters, famine, war, pain and suffering, which will wipe out 75% of all life on the earth before part two of the Second Coming takes place." When your religion teaches crap like this, then violent imagery isn't just accepted, it's encouraged. It's religious.
This is also an attempt to portray herself as crucified by those who would use her political blood in their proverbial Matzos. She's dabbling in blood metaphors while she spouts off about American exceptionalism. This isn't code; it's all CAP LOCK all the time, a blatant shout out to the violent fans who share her violent religion.
Besides being sloppy politics, this is just a sickening extension of her violent imagery. Rather than cooling her blood lust, as her taking down of the target map suggested she might, she is ramping it up, this time to include anti-semitic slurs in her response to Jews being murdered and maimed. That takes a special kind of sick mind. To continue violent imagery after this tragedy is deranged, but it is not a mistake on her part. It is a blatant call to her End Timers: keep spewing forth the hate, keep ramping up the violent imagery, keep threatening those you disagree with, because Jesus will be back soon and as long as you believe in him you won't wind up in the great tribulation like the other non-believers. You can encourage violence and even commit it yourself as long as you repent and accept Jesus before it's too late. In fact, violence is down right God-like.
These people are truly sick. I think I'll go back to ignoring them.