Palin unnerved the Left more than anything in several decades. They saw the thousands who came out to hear and cheer her speeches. They saw the massive throngs of people who stood in line for hours during nighttime freezing temperatures for her book-signings.
They saw what Palin tapped into. And it’s their most primal fear... a populist/conservative revolt from mid-america, aimed against their elite power bases, within their towers of government, the media, and the culture. A direct threat to to their entire, constantly steamrolling, leftist agenda. The GOP and its dottering old politicos have never been a threat to them. But they rightfully saw in Palin something that could indeed derail them. Thus the unhinged hellfire directed towards her.
Oh, you nailed it there.
Cruz has the same effect on them.
I wish Palin or Cruz or both would call us all to come out and protest. I really believe millions would get in the streets if she suggested it. Of course, the NSA could always come up with something to arrest her for.