The last straw [View all]

I've been quiet way too long. I've got to get this off my chest or I'll explode. First I need to describe why I've not spoken out any earlier. I work for a news network that tries to remain neutral on political matters. In fact should I reveal my true identity when expressing any political views of any kind that would be grounds for termination. I am a true lefty and always have been despite my upbringing in the Deep South. I'm over 60 by a few years, white and male which everyone assumes means I'm a right wing bigoted Republican. At least until I decide to tell them otherwise. I grew up in both large towns, small ones and rural areas of Alabama, Mississippi and Tennessee. I was educated in 8 different public schools, none of which were integrated. My dad was an extreme right wing Conservative Christian minister in the Southern Baptist Church.
I have 4 younger siblings. One a long time lefty like me and one who switched from the right to the left because he married a lefty. My sister-in-law and I are in lock step on almost every issue. My two remaining siblings are extreme right wingers of the worst type. In the interest of family peace we have an unspoken rule to never discuss politics when any member of the opposite political persuasion is within earshot.
This has worked well until recently when my sister started sharing her extremist views on Facebook. All her posts are now polluting my wall. Surely she knows that I'm seeing this garbage. Out of curiosity I started checking out some of these posts from the dark side and I was shocked into disbelief at the venomous hateful garbage that these people pass among themselves as "the truth".
A recent example is the "Romney won the debate but had a really hard time doing so since he had to debate two people at once, Candy and Obama". In spite of overwhelming evidence, video tape from every network, they still belief that Obama didn't say terrorism on 9/12 and Candy is a liar for saying that he did. I could give a hundred examples but why bother. There are hundreds of thousands of Republicans who will be totally shit upon by their Republican leaders if they gain power in the Congress and Presidency. These people, many of whom I grew up with and are close family members will vote against their own best interest just to keep a black man out of the White House.
Even my sister who recently relayed a message that one of her close friends who didn't have health insurance was "stabilized" and sent home after a heart attack then hit with a bill for the ER for over $30,000 which he did not have and now is facing bankruptcy 3 years before he becomes Medicare eligible answered and said.... Now here is the "LAST STRAW". This is all Obama's fault! Had he not pushed Obamacare through none of this would have ever happened. Even my highly successfully, well educated sister agrees with all the other insane right wing conservatives out there. I know it's getting close to the holidays and I'll have to see her again. I'm about to explode holding this in. Should I cut her and other old friends and family that believe this crap or should I get into a verbal confrontation that probably will split the family apart or should I continue and just ignore this? HELP!