It was in the Newsweek link that I referred to in another post.
From:
http://www.newsweek.com/myths-cost-democrats-presidential-election-521044
Here are a few tastes of what was in store for Sanders, straight out of the Republican playbook: He thinks rape is A-OK....Yes, there is an explanation for it—a long, complicated one, just like the one that would make clear why the Clinton emails story was nonsense. And we all know how well that worked out. Then there’s the fact that Sanders was on unemployment until his mid-30s, and that he stole electricity from a neighbor after failing to pay his bills, and that he co-sponsored a bill to ship Vermont’s nuclear waste to a poor Hispanic community in Texas, where it could be dumped. You can just see the words “environmental racist” on Republican billboards...Also on the list: Sanders violated campaign finance laws, criticized Clinton for supporting the 1994 crime bill that he voted for, and he voted against the Amber Alert system....Worst of all, the Republicans also had video of Sanders at a 1985 rally thrown by the leftist Sandinista government in Nicaragua where half a million people chanted, “Here, there, everywhere/the Yankee will die,’’ ...Sanders said, on camera, supporting the Sandinistas was “patriotic.” The Republicans had at least four other damning Sanders videos (I don’t know what they showed), and the opposition research folder was almost 2-feet thick. (The section calling him a communist with connections to Castro alone would have cost him Florida.)
Ok, not exactly "death to America" (I took some artistic liberties there) but "Yankee will die" isn't really that much better in my opinion.
If you knew about them, then I'd say you are definitely in the minority, as they were never major issues during the primaries.
Some might. The bigger risk though is that moderates might simply decide to stay home.
The political spectrum is not some binary hardcore republican/democrat split. There are shades of grey. Being a moderate means that you fall closer to the center of the political spectrum than the far left. Maybe you may even be a former republican voter who decided that the republican party had gone insane and you now feel more at home in a Democratic party that is fiscally conservative and liberal when it comes to social policies. Bringing in a leader who promotes policies that you think are too extreme (ones that threaten to drive up your taxes for example, or ones that are seen as anti-business) may make you decide that its just not worth it to vote.
Remember, while there are polls showing how Sander's policies were popular, polls don't often incorporate the costs. Take for example his promise of "free college". Yeah, lots of people love the idea. But if the republicans point out that "this will take money out of the pockets of hardworking taxpayers", many may decide that they just don't want to vote for that.